MARIA LUIZA CAIRES COMPER - unicid.edu.br · maria luiza caires comper efeitos do rodÍzio de funÇÕes na prevenÇÃo de distÚrbios osteomusculares relacionados ao trabalho Área

UNIVERSIDADE CIDADE DE SÃO PAULO

PROGRAMA DE MESTRADO E DOUTORADO EM FISIOTERAPIA

MARIA LUIZA CAIRES COMPER

EFEITOS DO RODÍZIO DE FUNÇÕES NA PREVENÇÃO DE

DISTÚRBIOS OSTEOMUSCULARES RELACIONADOS AO

TRABALHO

São Paulo

2015


EFEITOS DO RODÍZIO DE FUNÇÕES NA PREVENÇÃO DE

DISTÚRBIOS OSTEOMUSCULARES RELACIONADOS AO

TRABALHO

Tese de Doutorado apresentada ao

Programa de Mestrado e Doutorado em

Fisioterapia da Universidade da Cidade

de São Paulo, como requisito para

obtenção do título de Doutora, sob a

orientação da professora Dra. Rosimeire

Padula.

São Paulo

2015


EFEITOS DO RODÍZIO DE FUNÇÕES NA PREVENÇÃO DE DISTÚRBIOS

OSTEOMUSCULARES RELACIONADOS AO TRABALHO

Área de concentração: Avaliação, Intervenção e Prevenção em Fisioterapia

Data da Defesa: 17 de Dezembro de 2015

Resultado: ____________________________

BANCA EXAMINADORA:

Profª. Dra. Luciana Dias Chiavegato _________________________________________

Universidade Cidade de São Paulo

Prof. Dr. Leonardo Oliveira Pena Costa_______________________________________


Prof. Dr. Tabajara de Oliveira Gonzalez_______________________________________

Universidade Nove de Julho

Profª. Dra. Tatiana de Oliveira Sato___________________________________________

Universidade Federal de São Carlos

Profª. Dra. Rosimeire Simprini Padula ________________________________________


iii

“Eu sei o preço do sucesso: dedicação, trabalho

duro e uma incessante devoção às coisas que você quer ver

acontecer”.

Frank Lloyde Wright

iv

DEDICATÓRIA

Dedico este trabalho aos maiores amores de minha vida!

Aos meus pais, José Luiz e Maria da Conceição, por me presentearem com a vida,

com o amor incondicional e com seus melhores gestos e palavras. O que seria de mim sem

vocês?

Ao meu marido, Aleçandro, e meus filhos: Letícia, Laura e Luiz Heitor. Vocês são a

minha razão de viver! Para vocês, eu sempre darei o meu melhor!

v

AGRADECIMENTOS

Este trabalho constitui o resultado de uma trajetória que teve inicio em 2010, quando

motivada pela necessidade de melhorar minha formação acadêmica, aumentar a produção

científica e aprofundar meus conhecimentos na área de atuação profissional, eu decidi

participar do processo seletivo para o Programa de mestrado em Fisioterapia da

Universidade Cidade de São Paulo. Não tenho dúvidas de que foi uma das decisões mais

acertadas que já tive na vida, pois durante esta trajetória eu pude aprender com os

melhores professores que poderia ter e conviver com colegas de diferentes regiões deste

imenso país. Em especial, não posso deixar de falar de minha orientadora, Profa. Dra.

Rosimeire Simprini Padula, que é uma destas pessoas raras. Ela acredita no melhor das

pessoas e se doa, sem medir esforços para que elas alcancem o sucesso. Com ela eu

aprendi tanto e sobre tanta coisa relacionada a pesquisa e tanto e muito mais sobre como

ser uma pessoa melhor e não desistir nunca. É impossível mensurar o quanto tenho em

mim por influência dela e o quanto sou grata por isso!

Durante estes 5 anos, eu vivenciei um período de grande amadurecimento

pessoal e profissional. Tive a oportunidade de: participar e apresentar trabalhos em

eventos nacionais e internacionais, publicar artigos científicos em revistas de grande

impacto para a Fisioterapia, ter um trabalho, selecionado como um dos 8 melhores

resumos do Congresso Brasileiro de Fisioterapia (2011), ter um projeto financiado pelo

CNPQ. Mas muito mais que isso, eu tive a oportunidade de compartilhar o conhecimento

adquirido com os alunos para os quais tive a oportunidade de ensinar, contruindo para

uma formação voltada para uma prática baseada em evidência.

Mas tudo isso só foi possível porque tenho em minha vida muito anjos colocados

em minha vida por Deus para que Seus planos e os meus sonhos pudessem ser

cumpridos! Eles ficaram atrás dos bastidores me oferecendo todo tipo de suporte e apoio

necessário. Eu sinceramente não tenho palavras para agrader tudo o que fizeram e fazem

por mim! Muito, muito,...,(mais um milhão de muito) obrigada a você:

Aleçandro Dias Gomes, por me motivar, apoiar e me fazer enxergar as coisas de

uma forma mais prática. Você é meu amor, melhor amigo e exemplo de pessoa;

Leticia, Laura e Luiz Heitor, por me permitir conviver com vocês e por me doar este

amor, carinho e ternura sem limites! Obrigada por entenderem todos os momentos em que a

vi

mamãe teve que se ausentar. É por vocês que eu consegui forças para sempre seguir lutando

em busca do melhor para a nossa família.

José Luiz Comper e Maria da Conceição Caires Silva Comper, por serem os maiores

torcedores do meu sucesso e por isso, fazer o (im)possível para que ele pudesse ser alcançado.

Mãe, você é meu exemplo de vida e de superação. Pai, você é meu meu exemplo de

humildade e simplicidade. E juntos vocês são meu conforto, porto seguro e os melhores pais

do mundo.

Rosimeire Simprini Padula, pois sem você o aprendizado não teria sido o mesmo.

Obrigada pela paciência, compreenssão, dedicação e por sempre acreditar em mim.

Gabriela dos Santos Evangelista (meu braço direito), por tudo o que fez e faz por

mim. Você é simplesmente incrível: é dedicada, esforçada, competente e muito mais.

Não tenho palavras para agredecer. Obrigada por todo o suporte de sempre e, especialmente,

pelo seu auxílio nas atividades da empresa e do projeto de pesquisa;

Klênia Solis Carrazza (meu braço esquerdo), por ter assumido minhas atividades da

coordenação nos períodos mais críticos e necessários. Também não tenho palavras para te

agradecer. Obrigada por compartilhar comigo sua sabedoria e amizade.

Trifil (Gestores e Trabalhadores da empresa), por terem me dado a oportunidade de

realizar este projeto de pesquisa. Sem vocês esta trajetória não teria sido possível.

Renata Gonçalves Dantas, por compartilhar comigo sua amizade, seus conselhos e

desesperos também. Obrigada pelos dias e noites de trabalho duro compartilhados ao longo

destes anos, pelas viagens de estudo e por todos os nossos momentos de conversa sem cunho

científico. Ah! E porque não agardecer pelo serviço de baby sister nos momentos necessários.

Luiz Alfredo Omena, Ana Lúcia Bonfim e Odília Moliterni, por sempre terem

permitido que eu me ausentasse de minhas tarefas na universidade em busca de uma maior

qualificação profissional.

Adson Victor, Caique Simões e Roberto Paes, vocês foram incríveis por abrir mão das

férias para me auxiliar na tabulação dos dados. Sou muito grata por isso.

D. Rosi, D. Marineide e D. Eliete, no dia-a-dia e durante as minhas ausências,

vocês conseguiram cuidar de minhas crianças e casa, oferecendo todo o apoio afetivo e

cuidado necessário.

Todos aqueles outros anjos, por permitirem, diretamente e indiretamente, que este

trabalho pudesse ser concluído.

vii

Por fim, agradeço a meu Deus maravilhoso e perfeito, por estar presente em minha

vida durante esta caminhada; por cuidar de mim; e, por possibilitar que meus sonhos se

realizassem da melhor forma. Senhor, Graças a Louvores rendo a ti por tudo isso!

Maria Luiza Caires Comper

viii

PREFÁCIO

Esta tese de doutorado aborda temas relacionados ao rodízio de função enquanto

estratégia de prevenção dos distúrbios musculoesqueléticos e controle dos fatores de risco

biomecânicos em trabalhadores da indústria de manufatura. Está apresentada no formato

híbrido, como proposto pelo Programa de Mestrado e Doutorado em Fisioterapia da

Universidade Cidade de São Paulo, que permite a inclusão de artigos publicados, aceitos,

submetidos ou em preparação para publicação no corpo do texto da tese. É constituída por 6

capítulos, sendo que cada um deles apresenta a sua própria lista de referências bibliográficas e

de materiais complementares.

O capítulo 1 apresenta uma contextualização de temas relevantes que permitem ampla

abordagem sobre rodízio de função, tais como: origem, conceitos, teorias, objetivos da

adoção, critérios para organização, etapas de implantação e evidências científicas relacionadas

à sua efetividade enquanto estratégia de prevenção dos distúrbios musculoesqueléticos e

controle dos fatores de risco biomecânicos em trabalhadores da indústria de manufatura. Este

capítulo também inclui os objetivos e a justificativa do estudo.

O capítulo 2 apresenta o artigo “The effectiveness of job rotation to prevent work-

related musculoskeletal disorders: protocol of a cluster randomized clinical trial”,

publicado no periódico BMC Musculoskeletal Disorders, em 22 de maio de 2014. O objetivo

deste capítulo foi descrever, em maiores detalhes, os métodos de pesquisa do ensaio clínico

controlado e randomizado por cluster.

O capítulo 3 apresenta o artigo denominado “Job Rotation Designed to

Musculoskeletal Risk Control and Disorders in Manufacturing Industries: A Systematic

Review”. Este capítulo tem como objetivo revisar sistematicamente as evidências atuais sobre

efetividade e estratégias de implantação do rodízio de função como estratégia de controle de

risco e doenças em indústrias de manufaturas. Esta formatado de acordo com as normas do

periódico Applied Ergonomics, para o qual o artigo sera submetido. As normas de publicação

desse periódico podem ser encontradas ao final do texto, anexo a essa tese.

O capítulo 4 apresenta o artigo denominado “The Effectiveness of Job Rotation to

Prevent and Control Work-Related Musculoskeletal Disorders: A Cluster Randomized

Clinical Trial”. Este capítulo tem como objetivo apresentar os resultados obtidos por meio

do ensaio clínico randomizado por cluster, que avaliou a efetividade do rodízio de função

ix

como estratégia de prevenção e controle dos distúrbios musculoesqueléticos relacionados ao

trabalho. O artigo esta formatado de acordo com as normas do periódico The Journal of the

American Medical Association (JAMA), para o qual o artigo sera submetido. As normas de

publicação desse periódico podem ser encontradas ao final do texto, anexo a essa tese.

O capítulo 5 apresenta a descrição das etapas de implantação do projeto de pesquisa e

das barreiras encontradas. Também apresenta uma sucinta discussão das lições aprendidas no

decorrer da pesquisa. Pretende-se que estas informações possam ser usadas para a escrita de

um artigo de opinião sobre as principais barreiras e lições aprendidas durante a implantação

de um programa de rodízio de função.

O capítulo 6 apresenta as considerações finais da tese, bem como perspectivas de

estudos futuros sobre o tópico. Este capítulo também apresenta um contexto histórico de

apresentações de trabalho em congressos e desenvolvimento de pesquisas de iniciação

cientifica desenvolvidas em consonância com o presente estudo.

Em relação aos aspectos éticos e de registro, o projeto de pesquisa “The effectiveness

of job rotation to prevent work-related musculoskeletal disorders: a cluster randomized

clinical trial” foi aprovado pelo Comitê de Ética em Pesquisa da Universidade Cidade de São

Paulo (protocolo nº 18170313.5.0000.0064) e foi prospectivamente registrado no

ClinicalTrials.gov (NCT01979731). O projeto foi financiado pelo Conselho Nacional de

Desenvolvimento Científico e Tecnológico (CNPq ) (473651 / 2013-0).

A revisão sistemática foi registrada no International Prospective Register of

Systematic Reviews–PROSPERO (CRD42014013319). A realização deste estudo de revisão

e a formulação de uma nova equação para auxiliar no planejamento das escalas de rodízio,

que também fazem parte do estágio de pós-doutorado da profa. Dra. Rosimeire Simprini

Padula, em Boston, Massachussets, EUA, teve suporte de financiamento do CNPq

(249621/2013-4).

x

RESUMO

Contextualização: O rodízio de funções é uma estratégia ergonômica organizacional,

frequentemente utilizada em linhas de produção industrial. Ele é usado para aumentar o

desempenho, autonomia e flexibilidade dos trabalhadores e reduzir a exposição contínua aos

fatores de risco para doenças músculo-esqueléticas. Contudo, a eficácia do rodízio como

estratégia de prevenção e controle de distúrbios osteomusculares não possui sustentação

científica adequada.

Objetivos: Avaliar a efetividade do rodízio de função como estratégia de prevenção de

prevenção dos distúrbios musculoesqueléticos e controle dos fatores de risco biomecânicos

em trabalhadores da indústria de manufatura, e, sintetizar evidências relacionadas a

efetividade do rodízio de função e aos parâmetros utilizados para organizar as escalas de

rodízio nas indústrias de manufatura.

Métodos: Trata-se de uma revisão sistematica e um estudo controlado, randomizado por

cluster. Para a revisão, realizou-se buscas sistematizadas nas bases de dados: Medline,

Embase, ISI Web of Knowledge, CINAHL, Psyinfo, Scopus e SciELO. Os artigos localizados

foram avaliados por dois avaliadores independentes, que extraíram os dados para análise e

tabulação. O ensaio clínico foi realizado em que 4 setores de produção (957 trabalhadores)

uma indústria têxtil, randomicamente divididos entre o grupo de intervenção e o grupo

controle. O grupo intervenção realizou rodízio de função e orientações ergonômicas. O grupo

controle recebeu apenas as orientações ergonômicas. O desfecho primário foi o número de

horas de trabalho perdidas por afastamento do trabalho por licença médica decorrente de

doença do sistema osteomuscular e do tecido conjuntivo, mensurado em quatro intervalos de

três meses. Os desfechos secundários foram mensurados antes e após a intervenção e incluiu:

sintomas musculoesqueléticos, fatores de risco para a ocorrência dor musculoesquelética,

fatores de risco psicossociais e fadiga, estado geral de saúde, produtividade e custos. Os

efeitos da intervenção foram calculados usando modelos lineares mistos, seguindo os

princípios de intenção de tratamento.

Resultados: Quinze estudos foram incluídos na revisão sistemática. Foram identificados dois

estudos com boa qualidade metodológica, que tiveram resultados conflitantes, por serem

fortemente influenciados pelos modelos de produção, organização e execução do rodízio de

xi

função. Os paramêtros descritos para criação das escalas de rodízio possuem grande

variabilidade, mas na maioria dos estudos, os fatores biomecânicos e organizacionais foram

os mais utilizados. Contudo, houve semelhança nos intervalos de alternância, que tende a

variar entre uma ou duas horas. Em relação ao ensaio clínico, a amostra final incluiu 2

departamentos no grupo de intervenção (N = 266) e 2 departamentos no grupo controle (N =

255). Após 12 meses, o programa de de rodízio de função não promoveu efeitos significativos

no número de horas de trabalho perdidas em razão de licença médica por distúrbios

músculoesqueléticas. Não houve diferença em favor do grupo de intervenção (M -5.6 horas,

95% IC -25,0 para 13,8). Também não houve diferenças entre os grupos para os desfechos

secundários (P> 0,05).

Conclusão: Os resultados gerais da revisão sistemática sugerem a evidência do rodízio como

estratégia para prevenção e controle de distúrbios osteomusculares é bastante limitada,

principalmente em razão da qualidade metodológica dos estudos e da ausência de ensaios

controlados randomizados. O grupo rodízio não foi mais eficaz do que o grupo controle na

prevenção de distúrbios osteomusculares em trabalhadores industriais para diminuir o número

de horas de trabalho perdidas devido a doença ou sintoma osteomuscular e para prevenir e

controlar doenças músculo-esqueléticas.

Palavras-chave: Rodízio de função, Ergonomia, Indústria, Absenteismo, Distúrbios

Musculoesqueléticos

xii

ABSTRACT

Background: Several reasons justify the use of job rotation as an organizational strategy for

industrial production lines. It is used for increasing performance, autonomy and flexibility of

workers and alternate continuous exposure to risk factors for musculoskeletal disorders.

However, the effectiveness of job rotation to prevent and control musculoskeletal complaints

has limited evidence.

Objective: To assess the job rotation effectiveness as a strategy for the prevention of

musculoskeletal disorders and control of biomechanical risk factors in manufacturing

industrial workers, and synthesize evidence regarding the job rotation effectiveness and the

parameters used to organize job rottaion scales in manufacturing industries.

Studies Design: These are a systematic review and a cluster randomized controlled trial. To

review, systematic searches were conducted in the electronic databases: Medline, Embase, ISI

Web of Knowledge, CINAHL, Psyinfo, Scopus and SciELO. Two independent evaluators,

who extracted the data for analysis and tabulation, assessed the papers. The clinical trial was

performed in which 4 production sectors (957 employees) a textile industry, randomly divided

between the intervention group and the control group. The intervention group performed job

rotation and ergonomic guidelines. The control group only received ergonomic guidelines.

The primary outcome measure was absence from work due to sick leave measure in 3-months

follow-up. Secondary outcomes were measured at baseline and 12-month follow-up and

included: musculoskeletal symptoms, job factors for musculoskeletal pain and disorders,

psychosocial factors and fatigue, and general health and productivity. The effects of the

intervention were calculated using linear mixed models following intention-to-treat principles.

Results: Fifteen studies were included in the systematic review. Two studies of good

methodological quality were identified and showed conflicting results, because they are

strongly influenced by models of production, organization and execution of the job rotation.

The parameters described for creating the rotation schedules have greater variability, but in

most studies, biomechanical and organizational factors were the most used. However, there

was a similarity in rotation intervals, which varies between one to two hours. Regarding the

clinical trial, the final sample included 2 departments into intervention group (N=266) and 2

into control group (N=255). After 12 months, the job rotation program did not significantly

xiii

change its effect on number of working hours lost due to the sick leave caused by

musculoskeletal injury. There was no difference in favor of the intervention group (MD -5.6

hours, 95% CI -25.0 to 13.8) at 12-month follow-up. There were also no differences between

groups for the secondary outcomes (P > 0.05).

Conclusion: Overall results of the systematic review suggest that there is no evidence of job

rotation as a strategy for prevention and control of musculoskeletal disorders, mainly due to

the methodological quality of the studies and the absence of randomized controlled trials. The

job rotation program was no more effective than the control group in preventing

musculoskeletal disorders in industrial workers for decreasing the number of working hours

lost due to musculoskeletal symptom or disease and to prevent and control musculoskeletal

disorders.

Keywords: Job rotation, Ergonomic, Industry, Absenteeism, Musculoskeletal Disorders

xiv

SUMÁRIO

Prefácio ................................................................................................................................... viii

Resumo ...................................................................................................................................... x

Abstract .................................................................................................................................... xi

Capítulo 1 ................................................................................................................................ 15

Contextualização ................................................................................................................... 15

Objetivos da Tese .................................................................................................................. 21

Referências ............................................................................................................................ 22

Capítulo 2 ................................................................................................................................ 27

Artigo 1: The effectiveness of job rotation to prevent work-related musculoskeletal

disorders: protocol of a cluster randomized clinical trial .................................................... 27

Capítulo 3 ................................................................................................................................ 34

Artigo 2: Job Rotation Designed to Musculoskeletal Risk Control and Disorders in

Manufacturing Industries: A Systematic Review .................................................................. 34

Capítulo 4 ................................................................................................................................ 86

Artigo 3: The Effectiveness of Job Rotation to Prevent and Control Work-Related

Musculoskeletal Disorders: A Cluster Randomized Clinical Trial ...................................... 86

Capítulo 5 .............................................................................................................................. 113

Desdobramentos do Estudo – Lições Aprendidas .............................................................. 113

Execução do Projeto de Pesquisa ........................................................................................ 113

Lições Aprendidas ............................................................................................................. 115

Referências .......................................................................................................................... 116

Capítulo 5 .............................................................................................................................. 117

Considerações Finais .......................................................................................................... 117

Idealização da Revisão Sistemática, Conclusões e Desdobramentos ................................. 117

Idealização do Ensaio Clínico, Conclusões e Desdobramentos .......................................... 119

Referências .......................................................................................................................... 120

Anexos e Apêndices

15

CAPÍTULO 1

Contextualização

Os trabalhos nas indústrias de manufatura são organizados mediante o planejamento e

a gestão da produção que deve atender aos requisitos técnicos e de capacitação do

trabalhador1. Para tanto, as indústrias utilizam os princípios de produção Taylorista, Fordista

e, mais atualmente o Sistema Toyota de Produção ou Lean Production1,2

, que objetivam

melhorar a performance e eficiência do trabalhador, com economia de tempo e custos2. Estes

princípios são caracterizados, respectivamente, pelo (1) fracionamento e especialização de

tarefas, (2) redução dos movimentos desnecessários e intensificação do trabalho por meio de

linhas de montagem móvel, e, (3) flexibilização de produtos e mão de obra com alto controle

de qualidade e eliminação de desperdícios1, 2

. Isto faz com que a maior parte das operações

produtivas sejam caracterizadas por tarefas padronizadas, repetitivas e com curtos ciclos de

tempo3. Estas características, associadas à presença fatores de risco físicos (movimentos

repetitivos; força excessiva; postura inadequada, estática e/ou prolongada, vibração, e,

compressão tecidual), organizacionais (excesso de jornada de trabalho; ausência de intervalos

e pausas) e cognitivos (complexidade da tarefa, decisões complexas, altas demandas

psicológicas, concentração, atenção) podem contribuir para o surgimento de distúrbios

musculoesqueléticos relacionados ao trabalho3-5

.

Os distúrbios osteomusculares relacionados ao trabalho (DORT) são definidos como

uma síndrome clínica relacionada ao trabalho, caracterizada pela ocorrência de diversos

sintomas musculares, concomitantes ou não, que resultam em incapacidade funcional,

temporária ou permanente6. Estes distúrbios incluem uma variedade de condições

inflamatórias e degenerativas que afetam músculos, tendões, ligamentos, articulações e nervos

periféricos e podem comprometer a coluna, pescoço, ombros, cotovelos, antebraços, punhos e

mãos3. A fisiopatologia da DORT pode ser explicada pelo modelo conceitual proposto por

Armstrong (1993)7. De acordo com este modelo, a DORT resulta da deficiente capacidade

biológica natural de recuperação do tecido frente às alterações fisiológicas inflamatórias

mantidas por um longo período de tempo7. Em outras palavras, a DORT se manifesta quando

não há tempo suficiente para a regeneração tecidual completa.

No cenário industrial, a DORT representa um grande problema econômico por afetar a

produtividade e qualidade da produção e aumentar os custos diretos e indiretos causados pelos

16

dias de trabalho perdidos8,9

. Estima-se que, somente no ano de 2012, os EUA desembolsaram

227 bilhões para reduzir as perdas de produtividade decorrente dos dias de trabalho perdidos

por doenças, incluindo as DORT9. Diante deste cenário, torna-se imperativo a realização de

intervenções efetivas que favoreçam a prevenção dos distúrbios musculoesqueléticos e

controle dos fatores de risco ocupacionais10. Dentre as intervenções mais recomendadas estão:

o redesenho de postos de trabalho, adequação de mobiliários, máquinas e ferramentas,

orientações ergonômicas, pausas para descanso e rodízio de funções3.

O rodízio de funções é uma das intervenções organizacionais mais praticadas nas

indústrias de manufatura11-14

, tendo origem nas indústrias japonesas, no final dos anos 5015

.

Nos EUA, o interesse pelo rodízio ocorreu nos anos 80, quando engenheiros e gestores

passaram a adotá-lo como uma alternativa para aumentar a performance, flexibilidade e

autonomia dos trabalhadores industriais, reduzindo assim, os custos de produção13,16-20

. Os

efeitos positivos do rodízio, do ponto de vista dos gestores, foram tantos que, no ano de 1992,

26% das indústrias americanas realizavam rodízio de tarefas com mais da metade de seus

funcionários21

. Em 2007, esse número praticamente dobrou, uma vez que 42,7% das

indústrias localizadas no centro-oeste dos Estados Unidos adotavam alguma forma de

rodízio22

.

Existem três principais teorias que tentam explicar o motivo da grande adesão ao

rodízio de função pelas indústrias em geral. São elas: Teoria da aprendizagem do

trabalhador; Teoria da aprendizagem do empregador e Teoria da motivação23

. A primeira

teoria está fundamentada no fato de que, ao realizar o rodízio, o trabalhador é exposto a

tarefas que requerem diferentes competências e habilidades24

. Isso faz com que ele adquira

novos conhecimentos e experiências25

, tenha uma compreensão mais profunda do processo

produtivo e seja flexível para alocação em diferentes tarefas, a critério da necessidade de

produção23

. A teoria da aprendizagem do empregador defende a ideia de que o rodízio fornece

informações sobre as habilidades do trabalhador, uma vez que seu desempenho pode ser

observado em cada uma das tarefas por onde ele passa23

. Por fim, a teoria da motivação tem

como prerrogativa o fato de que o rodízio torna o trabalho mais interessante23

. Contudo,

nenhuma das teorias defende o uso do rodízio como estratégia de prevenção e controle dos

distúrbios osteomusculares. O que pode estar relacionado ao fato de que o rodízio teve origem

a partir da necessidade de reduzir custos e flexibilizar a produção13,16,20

.

Com o passar do tempo, além de atender as necessidades de gerenciamento da

produção, o rodízio passou a ser adotado como uma estratégia de prevenção dos distúrbios

17

musculoesqueléticos e controle dos fatores de risco biomecânicos, inclusive com suporte

técnico de agências federais de saúde e segurança, como a OSHA, NIOSH e, no Brasil, a

Norma Regulamentadora nº 17 (NR-17) 26,27

indica a necessidade de revezamento das

posturas de trabalho, de modo a que o trabalho se adeque as caracteristicas psicofisiológicas

dos trabalhadores, sendo o rodizio de função entendido como tal. A premissa é de que, ao

alternar entre tarefas de maior e menor risco, o rodízio reduz a sobrecarga biomecânica

acumulada em uma parte específica do corpo28

. Isso porque, a alternância da exposição

possibilita a recuperação de um grupo muscular enquanto outros grupos estão sendo

solicitados3,29

. Neste caso, o rodízio deveria ser recomendado para tarefas repetitivas, estáticas

ou monótonas3, de manuseio e transporte de carga

29 ou que possua posturas inadequadas e

estáticas30,31

. Ele poderia ser usado para aliviar os efeitos da sobrecarga muscular, monotonia

e estresse32

, reduzir o absenteísmo33,34

, favorecer a inclusão de trabalhadores com

incapacidade temporária ou permanente18

, e aumentar a satisfação do trabalhador35

.

A variedade de propósitos do rodízio pode explicar o grande número de termos

empregados e conceitos utilizados para defini-lo. Rodízio de tarefas, rodízio de funções,

rodízio de posições e trabalhadores multifuncionais são alguns dos termos encontrados nos

artigos que descrevem o rodízio de função36

. Em termos conceituais, o rodízio de funções

pode ser definido sob dois pontos de vista. Em relação ao gerenciamento/produção, Jorgensen

et al.22

e Huang24

definem o rodízio de funções como um sistema de trabalho que permite aos

trabalhadores alternar entre tarefas que solicitam diferentes habilidades e responsabilidades. É

uma forma de possibilitar uma formação complementar para os trabalhadores, o que permite

que adquiram novos conhecimentos e experiências em tarefas e/ou setores diferentes25

. Do

ponto de vista de prevenção dos distúrbios musculoesqueléticos, o rodízio é definido como a

alternância entre diferentes níveis de exposição ao risco biomecânico ou de demandas

físicas22,37

. Atualmente, estes dois conceitos têm sido integrados, de modo a possibilitar que o

rodízio promova os efeitos positivos para a indústria e para os trabalhadores.

Apesar de todas as vantagens já apresentadas, na prática, o rodízio de funções não é

tão simples de ser implantado nas indústrias. Algumas são as razões para que isto aconteça,

tais como as determinações da legislação brasileira, por meio da Consolidação das Leis do

Trabalho (CLT) 38

, que diz que a troca entre diferentes funções só pode ocorrer se for para

cargos mais elevados. Isto dificulta rodízio de trabalhadores entre setores e entre tarefas de

diferentes graus de complexidades39

. Segundo, porque a implantação da proposta (ideal)

planejada, muitas vezes, esbarra nas características da tarefa, organização do trabalho, espaço

18

físico e número de trabalhadores. Por fim, porque a execução do rodízio dependerá da

convicção dos gestores sobre a importância desta estratégia e da aceitação dos trabalhadores

em realizá-la39

.

A implantação de um programa de rodízio deve cumprir algumas etapas, que incluem:

(1) identificação das possíveis tarefas para realização do rodízio; (2) análise dos níveis de

complexidade destas tarefas e das competências e habilidades necessárias para realizá-las; (3)

análise das demandas e nível de risco biomecânico; (4) planejamento da escala de rodízio,

incluindo a sequência e frequência; (5) treinamento dos trabalhadores; e, (6) implantação e

acompanhamento.

As etapas de identificação e análise das tarefas à serem incluídas no programa de

rodízio são de grande importância, já que fornecem as informações necessárias para que a

alternância entre os níveis de exposição e a redução do estresse físico e cognitivo sejam

efetivos. Dentre as informações a serem analisadas, estão: número de trabalhadores e de

tarefas envolvidas, habilidades e competências necessária para execução da tarefa, nível de

exposição, região corporal solicitada, frequência de movimentos, duração da exposição,

micropausas, duração, dentre outros12,22,40

. As habilidades e competências dos trabalhadores

podem ser calculadas por meio de curvas de aprendizado39

, enquanto os aspectos

biomecânicos podem ser avaliados por meio dos métodos de análise do risco ergonômico, tais

como: Quick Exposure Check (QEC)41

, Rapid Entire Body Assessment (REBA)36

, Rapid

Upper Limb Assessment (RULA)37

, etc.

O planejamento do rodízio é determinado baseando-se nas informações coletadas

anteriormente e nos seguintes critérios: (1) principal demanda física (manuseio de materiais,

repetição de movimentos, postura estática); (2) postura predominantemente adotada para a

realização da tarefa (sentada, ajoelhada, em pé, andando); (3) regiões corporais de maior

sobrecarga (ombros, cotovelos, punhos, mãos, coluna); e, (4) nível de intensidade da

exposição (baixo, moderado, alto ou muito alto). A autonomia do trabalho (técnicas e ritmo

de trabalho) e o uso de máquinas e ferramentas também devem ser avaliados42

. É importante

destacar que, nas situações em que o rodízio for proposto com o objetivo de modificar os

padrões de exposição ergonômica, os trabalhadores deverão realizar alternância entre tarefas

de baixo, moderado e alto risco ergonômico e com diferentes solicitações biomecânicas por

região corporal22,37

. O planejamento inadequado do programa de rodízio não só torna a

19

intervenção ineficaz, como pode resultar em aumento dos níveis de exposição para os

trabalhadores43

.

A etapa seguinte, compreende a organização da sequência de tarefas a serem

alternadas. Para auxiliar nesta organização, alguns métodos e algoritmos foram desenvolvidos

para gerar escalas de alternância entre as tarefas a partir de diferentes critérios e

parâmetros11,12,18,30,32,44,45

. Um dos primeiros algoritmos foi desenvolvido por Carnahan et

al.46

para tarefas de manuseio de materiais e incluiu o Job Severity Index (JSI). Este índice

integra critérios de percepção do trabalhador sobre a capacidade de realizar atividades de

levantamento/manuseio de materiais para avaliar o potencial de risco de lesão em coluna

vertebral. Seguindo uma proposta parecida, Tharmmaphornphilas e Normam45

propuseram

um método heurístico mais robusto, que considerou como parâmetros o JSI e o número de

dias perdidos em razão de lesões em coluna lombar. Posteriormente, os algoritmos passaram a

incluir um maior número de parâmetros, que variam a depender da proposta do rodízio. Por

exemplo, Diego-Mas et al. (2009)40

construíram um algoritmo para prevenir a acumulação de

fadiga decorrente da repetição de movimentos. Este algoritmo incluiu parâmetros

biomecânicos (postura no trabalho, frequência e duração dos movimentos realizados);

organizacionais (capacidades gerais para a realização do trabalho, como dirigir, escrever,

falar, utilizar computador); cognitivos (tomada de decisões, autonomia, demandas cognitivas);

e, outros (aspectos ambientais e de segurança). De modo similar, outros algoritmos foram

propostos com o objetivo de reduzir os efeitos da repetitividade e fadiga11,47-49, e equilibrar os

efeitos do rodízio frente ao tédio/motivação do trabalhador em células de manufatura e

favorecer a aprendizagem de habilidades do trabalhador32

. É importante destacar que, apesar

de serem muitos, nenhum destes algoritmos foi avaliado em ensaios clínicos.

Sequencialmente, os trabalhadores devem ser treinados para a realização das tarefas

incluídas no programa de rodízio. Esta etapa é importante para que os trabalhadores tenham o

conhecimento e desenvolvam as competências e habilidades necessárias para lidar com todas

as etapas das tarefas produtivas, bem como garantir a qualidade dos processos e produtos

envolvidos nestas23

. A ausência de treinamento pode ser crítica para resultados positivos do

rodízio, uma vez que é preciso que o trabalhador compreenda o uso desta intervenção e

permita que novas competências sejam adquiridas50

. Além disso, a falta de treinamento

implica em redução da produtividade, aumento de custos por retrabalho e baixa qualidade dos

produtos39

; e, pode resultar em aumento das queixas musculoesqueléticas

51.

20

Diante do exposto, percebe-se que o rodízio de função: (1) pode contribuir para a

prevenção de distúrbios musculoesqueléticos e controle dos fatores de risco biomecânicos; (2)

possui uma metodologia própria, com etapas e parâmetros de planejamento e implantação; e,

(3) ultimamente, tem sido bastante utilizado nas indústrias de manufatura como estratégia de

controle de distúrbios musculoesqueléticos. Contudo, ainda existem várias lacunas científicas

que sustentem o uso desta intervenção. Primeiro, os estudos, em geral, não possuem qualidade

metodológica apropriada para avaliar a efetividade do rodízio, uma vez que a maior parte dos

estudos são transversais11,12,18,30,32,43-45,52,53 e nenhum estudo controlado randomizado foi

realizado até o momento. Segundo, a maioria dos estudos têm avaliado os efeitos do rodízio

em estudos retrospectivos em que esta intervenção foi adotada para atender as necessidades

de produção39,54. Neste caso, o programa de rodízio pode não ter sido adequadamente

planejado para que o nível de exposição ao risco biomecânico ocorresse. Aliás, a descrição

dos parâmetros utilizados como critério para definição da escala de rodízio representa outro

problema

Todas estas razões contribuem os recentes achados de uma revisão sistemática36

sobre

efeitos do rodízio de função sobre queixas musculoesqueléticas e parâmetros para

sustentabilidade de vida laboral foi publicada36

. Os autores concluíram que os resultados dos

16 estudos incluídos na revisão são conflitantes e inconsistentes36

. Isto porque existem alguns

estudos que mostram efetividade do rodízio de função para a prevenção dos distúrbios

musculoesqueléticos, enquanto outros não. Por exemplo, o estudo de Roquelaure et al.54

avaliou, por meio de um caso-controle, a associação entre os fatores organizacionais e

síndrome do túnel do carpo em três indústrias. Os resultados mostraram que, quando as

características individuais e relacionadas com o trabalho são controladas, a ausência do

rodízio está associada a 6,3 vezes maior chance de desenvolver a síndrome do túnel do carpo.

Kuijer et al. 53

, ao comparar grupos que realizavam ou não rodízio em um estudo transversal,

também encontraram reduções significativas da sobrecarga física em trabalhadores de um

departamento de coleta de lixo que realizaram rodízio entre a tarefa de dirigir e coletar lixo.

No entanto, ao realizarem em um estudo longitudinal, prospectivo, Kuijer et al. (2005)55

observaram que, a longo prazo, o rodízio aumentou a sobrecarga em outras regiões corporais

e, que os trabalhadores começaram a relatar mais dores lombares, principalmente para o

grupo que apenas dirigia. Este grupo manteve a exposição aos mesmos fatores de risco,

mesmo com a alternância das tarefas. Resultados similares foram obtidos por Frazer et al.43

,

que avaliou duas tarefas de manuseio de materiais, uma com baixo nível de sobrecarga e outra

com alto nível. O risco de dor lombar aumentou à medida que maior quantidade de tempo foi

21

empregada para realização da tarefa de maior sobrecarga, em razão dos efeitos cumulativos e

de pico de força43

. O estudo de Guimarães et al.39

avaliou a aquisição de competências por

parte dos trabalhadores em rodízio e os efeitos de rotação de empregos avaliados após 3,5

anos. Os resultados indicaram que não houve diferenças entre o aprendizado e a performance

entre os trabalhadores que realizavam e não realizavam rodízio. Além disso, houve redução

na ocorrência de acidentes e absenteísmo, melhora da produtividade e retrabalho, e maior

satisfação do trabalho para os trabalhadores que realizavam o rodízio.

Diante do exposto, verifica-se a real necessidade de estudos, de alta qualidade

metodológica que avaliem a efetividade do rodízio de função como estratégia de prevenção

para os distúrbios musculoesqueléticos. Assim, até o presente momento, as propostas deste

estudo são: revisar sistematicamente as evidências atuais sobre efetividade e estratégias de

implantação do rodízio de função como estratégia de controle de risco e doenças em

indústrias de manufaturas; e, avaliar o efeito do rodízio de funções na prevenção dos

distúrbios osteomusculares em trabalhadores industriais, por meio de um estudo clinico

controlado e randomizado por cluster. Este efeito será avaliado por meio da quantidade de

horas de trabalho perdidos em razão do afastamento por licença médica. A hipótese é de que o

grupo que realiza o rodízio tenha menor quantidade de horas perdidas por afastamento de

licença médica. Outros estudos relacionados ao planejamento do rodízio de função estão

sendo realizados.

Objetivos da tese:

Avaliar, por meio de uma revisão sistemática, a eficácia do rodízio como estratégia de

controle de risco e doenças e identificar os parâmetros utilizados para organizar as

escalas de rodízio nas indústrias de manufatura.

Avaliar, o efeito do rodízio de função na prevenção dos distúrbios

musculoesqueléticos em trabalhadores industriais, por meio de um estudo controlado e

randomizado por cluster.

22

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27

CAPÍTULO 2

ARTIGO 1

The effectiveness of job rotation to prevent work-related

musculoskeletal disorders: protocol of a cluster randomized

clinical trial

Publicado na revista: BMC Musculoskeletal Disorders

Comper MLC, Padula RS. The effectiveness of job rotation to prevent work-related musculoskeletal

disorders: Protocol of a cluster randomized clinical trial. BMC Musculoskeletal Disorders. 2014;15

28

29

30

31

32

33

34

CAPÍTULO 3

ARTIGO 2

Job Rotation Designed to Musculoskeletal Risk Control

and Disorders in Manufacturing Industries: A Systematic

Review

submetido à revista: Applied Ergonomics

35

Job Rotation Designed to Musculoskeletal Risk Control and Disorders in

Manufacturing Industries: A Systematic Review.

Rosimeire Simprini Padula, PhD1*

, Maria Luiza Caires Comper, MS1, Emily H. Sparer PhD

2,

Jack T Dennerlein, PhD3,4

1. Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São

Paulo, São Paulo, Brazil.

2. Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public

Health, Boston, Massachusetts, United States.

3. Department of Environmental Health, Harvard T.H. Chan School of Public Health,

Boston, Massachusetts, United States.

4. Department of Physical Therapy, Movement, and Rehabilitation Sciences Bouvé

College of Health Sciences, Northeastern University, Boston, Massachusetts, United States.

*Autor Correspondente

Rosimeire Simprini Padula

E-mail: [email protected]

Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, Rua

Cesario Galeno 475, 03071-000 - São Paulo-SP, Brazil.

Tel.: +55 11 21781564

mailto:[email protected]

36

ABSTRACT

To better understand job rotation in manufacturing industry we conduct a systematic review

asking the question do job rotation programs reduce overload and prevent musculoskeletal

disorders. We searched MEDLINE, EMBASE, Business Source Premier, ISI Web of

Knowledge, CINAHL, PsyINFO, Scopus and SciELO databases for articles published in

peer-reviewed journals. From 10.809 potential articles 71 were read for full text analysis. Of

the fifteen studies included for data extraction, three were intervention studies, one was a

case-control study, and eleven were cross-sectional studies. Only one study was scored with

good methodological quality. The studies reported mixed results, which appear to be

influenced by production models, organization and implementation of job rotation. Currently

little to no evidence exists supporting job rotation as a strategy for control and prevention of

musculoskeletal disorders. Better quality studies are needed to truly document the

effectiveness of job rotation.

Keywords: Task rotation, Ergonomics, Industrial workers

PROSPERO Registration Number: CRD42014013319

37

1. Introduction

Job rotation programs emerged in the 1980s and 1990s as an organizational strategy

with the goal of increasing the performance and the flexibility of workers (Cristini and

Pozzoli, 2010; Kernan and Sheahan, 2012). These programs have often been adopted by

engineers and managers to reduce the time and production costs (Azizi and Liang, 2013;

Corominas et al., 2006; Moreira and Costa, 2013). Initial motivations for implementing job

rotation programs was part of a lean production system and total quality, focused on the need

for more workers with more autonomy (Corominas et al., 2006; Cristini and Pozzoli, 2010).

Currently, job rotation programs are frequently recommended to mitigate continuous

exposure to risk factors for musculoskeletal disorders (Leider et al., 2015a; Mathiassen,

2006).

The definitions for the job rotation are many and vary according to the purpose for

which this strategy is adopted. In terms of management, it can be defined as an alternation

between workers tasks and jobs that require different skill and responsibility (Huang, 1999).

In terms of musculoskeletal risk control, job rotation is defined as a strategy to alternate the

workers between tasks with different exposure level and occupational demands (Howarth et

al., 2009; Jorgensen et al., 2005), which aims at avoiding overloading local body parts

(Mathiassen, 2006).

The planning and implementation of job rotation programs are most specific to each

professional sector and essential to the success of the intervention (Frazer et al., 2003). The

success depends on several criteria and parameters to generate the most effective job rotation

risk control and prevention of musculoskeletal diseases (Leider et al., 2015b). The main

criteria are to identify physical, cognitive and organizational demands; determine exposure

levels; and, evaluate and define how the job rotation schedule will be created. After that, all

workers should be trained to each job to develop the competence and skills and to ensure the

process and products quality (Guimarães et al., 2012). It is also necessary to consider others

factors, such as psychosocial (job satisfaction, engagement) and environmental, can affect

worker health outcomes and the success of the health promotion and prevention programs (Ho

et al., 2009; Park and Jang, 2010).

There are numerous reasons justified by the manufacturing industry and described in

the literature for the selection of job rotation as an ergonomic organizational strategy

(Corominas et al., 2006; Jorgensen et al., 2005). Therefore, studies that have evaluated the

38

effects of job rotation do not always use the same criteria to evaluate the positive or negative

aspects of this intervention, leading to challenges in practical application for practitioners and

researchers.

This review aims to identify evidence for the efecctiveness of job rotation on

improving musculoskeletal health, and investigates whether or not this evidence varies across

different implementation schemes. The definition of job rotation used in this study is the

rotation of workers to tasks with different exposure levels and job demands for workers who

have a daily load of 8 hours (480 minutes), with a lunchbreak.

The specific questions addressed in this review are:

1. What is the effect of job rotation in terms of

a) specific work-related musculoskeletal issues (disorders, complaints, pain and

discomfort),

b) exposure to know risk factors, specifically physical risk factors (posture, force,

biomechanics, fatigue, effort exertion) and

c) psychosocial (job satisfaction, stress, job control, engagement) in manufacturing

industry workers?

2) In addition, with this specific knowledge of the effects of job rotation, how should such

rotation be designed?

2. Methods

2.1. Search strategy

Independent searches were conducted in electronic databases: MEDLINE, CINAHL,

EMBASE, Business Source Premier, ISI Web of Knowledge, PsyINFO, Scopus and SciELO,

in English language, without restricting the publication date. The search terms were defined

based on the list of terms used in the systematic review studies of the Institute for Work &

Health and National Institute for Occupational Safety and Health (NIOSH). The search terms

were grouped into three categories according the principles of "PICO”. The following is an

example of the group terms: Population (Workers OR Employees); Intervention (Job rotation

OR Task rotation); Outcomes (Musculoskeletal disease OR Work ability). Groups of terms

used for search strategies can be seen in Appendix I. The last search was completed on

October 17, 2014.

39

2.2. Inclusion and Exclusion Criteria

The eligible studies included contained all of the following criteria: (1) population of

manufacturing workers; (2) exposures to known risk factors (biomechanical overload,

repetitive tasks, fatigue, posture at work, force, etc.) musculoskeletal disorders (pain,

discomfort, absenteeism), and psychosocial factors; (3) written in English; (4) full text papers

published in peer-reviewed journals; and (5) designed experimental and observational studies:

cohort, case-control, clinical trials and cross-sectional. Excluded studies included the

following: outcomes of productivity and costs only, outcomes that were assessed through

qualitative methods only, studies in which the definition of job ration was different than our

aforementioned definition and those that evaluated variability of factors within a single given

task without changing tasks. The search results were exported to EndNote ® X7 software

where duplicates were removed and extraction of data was obtained in full text.

2.3. Study Analysis

The review process consisted of first deciding which studies to include through review

of 1) the titles and, (2) reading the abstracts. If necessary then full text was reviewed. Two

independent researchers (RP and ML) completed the inclusion review. In cases of

disagreement between the two reviewers the decision was reached by consensus, or a third

researcher (ES) was consulted and the decision was made by arbitration.

Methodological Quality Assessment of Studies

Identified studies were then assessed for their quality according to criteria of internal

and external validity (Sanderson et al., 2007). We used the quality assessment tools proposed

by U.S. National Institutes of Health (NIH). These included for the Quality Assessment of

Controlled Intervention Studies (Appendix 2), Quality Assessment Tool for Observational

Cohort and Cross-Sectional Studies (Appendix 3) and Quality Assessment Tool of Case-

Control Studies (Appendix 4), which had 14 items and 12 items, respectively. Items in these

tools included: reporting; sample size; inclusion criteria; measures of exposure; assessment

bias; and, statistical analysis.

The quality rating was classified as good, fair or poor according to general analysis of

the evaluators considering all items described above. The study quality was determined by the

total number of positive (+) items and the rating classification adopted by Wong et al. (2008).

40

The studies with 67% or more positive items checks were an indication of good quality,

studies with 34-66% positive checks were an indication of fair quality, and 33% or less were

an indication of poor quality (Wong et al., 2008).

2.5. Data Extraction

Data extracted included the following: (1) year of publication; (2) the manufacturing

industry sector; (3) country where the study was conducted; (4) study design type; (5)

characteristics of participants; (6) task (e.g. repetitive with short cycles, handling load); (7)

methods for the organization of a job rotation (e.g. simple or using an equation); (8)

parameters used to define job rotation (e.g. biomechanics, organizational, cognitive, motor

learning curves, production aspects); and, (9) job rotation schedules (e.g. protocol, time, and

priorities). Two independent reviewers extracted the data and, in case of disagreement;

consensus was reached by discussion between the reviewers or by arbitration by a third

reviewer.

In the original proposal and PROSPERO register, it was indicated that meta-analysis

would be carried out. However, due to the large heterogeneity of study designs, criteria and

measuring instruments used in the studies, the analysis was not possible. Thus, results from

this study are presented descriptively.

3. Results

3.1. Characteristics of the studies and methodological quality

The search resulted in 10.809 potentially eligible studies, of which 1.362 were

duplicates, and 9.376 were excluded based on the review of the titles and abstracts. An

addition 56 studies were excluded after review of the full-text, leaving fifteen studies (Figure

1) for data extraction.

41

Figure 1- Flowchart of Systematic Review Process

The final fifteen studies were from five countries and the majority of which (eight

studies) examined assembly line area of Automotive/Automobile industry (Asensio-Cuesta et

al., 2012b; Asensio-Cuesta et al., 2012a; Dawal et al., 2009; Dawal and Taha, 2007; Diego-

Mas et al., 2009; Frazer et al., 2003; K. Fredriksson et al., 2001; Roquelaure et al., 1997).

Most of studies (nine) proposed job rotation schedules exclusively between tasks with short

cycle time and highly repetitive movements (Asensio-Cuesta et al., 2012b; Asensio-Cuesta et

al., 2012a; Balogh et al., 2006; Diego-Mas et al., 2009; Filus and Okimorto, 2012; Frazer et

al., 2003; Fredriksson et al., 2001; Roquelaure et al., 1997; Sato and Coury, 2009) (Table1).

From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(6): e1000097. doi:10.1371/journal.pmed1000097

Formoreinformation,visitwww.prisma-statement.org.

MEDLINE: 2483 CINAHL: 1538

EMBASE: 1078

Business Source Premier: 2754 Scopus: 2003

ScIELO: 420

ISI Web of Knowledge: 331 PsycINFO: 201

Screening

Included

Eligibility

Iden

tification

Relevant studies

(n = 10808)

Records screened

(n = 9446)

Records excluded

(n = 9376)

Full-text articles assessed for eligibility

(n = 71)

Excluded for final decision:

Other language (n=1)

Not full paper (n=7) Overload analyses (n=13)

Analysis of the tasks multiple (n=7)

Opinion text (n=7)

Guidance (n=2) Productivity equations (6)

Others populations (n=11)

Survey with manager and coordinators (n=2)

Results companies

together (1)

Studies included in qualitative synthesis

(n = 15)

Duplicates excluded

(n = 1362)

42

Table 1 - Characteristics of the studies included in Systematic Review

Of the 15 studies included, two were rated as good (Roquelaure et al., 1997), six as

fair (Balogh et al., 2006; Dawal et al., 2009; Dawal and Taha, 2007; Guimarães et al., 2012;

K. Fredriksson et al., 2001; Sato and Coury, 2009), and seven as poor methodological quality

(Asensio-Cuesta et al., 2012b; Asensio-Cuesta et al., 2012a; Carnahan et al., 2000; Diego-

Mas et al., 2009; Filus and Okimorto, 2012; Frazer et al., 2003; Tharmmaphornphilas and

Norman, 2007a).

The study designs consisted of three clinical trials (Comper and Padula, 2014;

Guimarães et al., 2012; K. Fredriksson et al., 2001), one case-control study (Roquelaure et al.,

1997) and eleven cross-sectional studies (Asensio-Cuesta et al., 2012b; Asensio-Cuesta et al.,

2012a; Balogh et al., 2006; Carnahan et al., 2000; Dawal et al., 2009; Dawal and Taha, 2007;

Diego-Mas et al., 2009; Filus and Okimorto, 2012; Frazer et al., 2003; Sato and Coury, 2009;

Tharmmaphornphilas and Norman, 2007a). Comper and Padula (2014) had not evaluated

methodological quality because it was a protocol study. The other two clinical studies were

non-randomized controlled trials and were rated as fair (Guimarães et al., 2012; K.

Fredriksson et al., 2001)(Table 2).

RCT CS C CC

Textile/Manufacturing cells Brazil x

Home appliances/Assembly line Brazil x

Automobile parts/Assembly line NR x


Footwear Brazil x


Office products Brazil x

Automotive Malaysia x

Automotive Malaysia x

Manufacturing cells NR x

Wooden boards for parquet

flooring/ Assembly linesSweden x

Automotive/Assembly line Canada x

Automobile/Assembly line Sweden x

Manufacturing cells NR x

Television, Shoes and Automobile

brakes France XHigh repetitive movements (under 30 seconds)

Manufacturing Industry Job characteristics

Not reported

Not reported

Lifting tasks.

Higher repetitive (67 seconds)

Repetitive movements (60 seconds)

Repetitive movements (cycle time between 15 and

90 seconds)

Repetitive (cycle shorter than 90 seconds)

High repetitive movements


Task with different complexities


Repetitive movements and Materials handling

CountryStudy Design

Task with different complexities

Lifting tasks

RCTs – Randomized Control Trial; CS – Cross Sectional; C - Cohort; CC – Case Control; NR not reported; NA – not applicable. Were used

the first´s author name on the tables.

43

Table 2- Methodological quality of studies

+ (Yes), - (No), NR - not reported, NA – not applicable, CD – cannot determine, T- Total punctuation; QR - Quality

Rating (67 % or more - Good, 33- 66% - Fair, 33% or less - Poor), Quality Tool - † Appendix 2 (Criteria:Randomization

(1 and 2): Allocation (3, 6 and 13); Blinding (4 and 5); Outcomes (9, 10 and 11); Dropout rate ( 7,8 and 12);

Confounding (14); ††Appendix 3 (Criteria: Setting (1 and 2); Allocation (3, 4 and 5); Outcomes (6,7,8,9,10,11 and 12);

Dropout rate (13); Confounding (14); †††Appendix 4 (Criteria: Setting (1 and 2); Allocation (3, 4, 5 and 6);

Randomization (7 and 8); Outcomes (9 and 10); Blinding (11); Confounding (12).

3.2 Job rotation outco mes measure

In terms of outcomes, eight studies examined clinical outcomes (disability, disorders,

pain, discomfort) (Balogh et al., 2006; Carnahan et al., 2000; Comper and Padula, 2014;

Guimarães et al., 2012; K. Fredriksson et al., 2001; Roquelaure et al., 1997; Sato and Coury,

2009; Tharmmaphornphilas and Norman, 2007a), seven studies examined changes in

exposure to physical risk factors (biomechanics, repetition, fatigue, effort exertion) (Asensio-

Cuesta et al., 2012b; Asensio-Cuesta et al., 2012a; Balogh et al., 2006; Diego-Mas et al.,

2009; Filus and Okimorto, 2012; Frazer et al., 2003), and three examined psychosocial factors

(job satisfaction) (Comper and Padula, 2014; Dawal et al., 2009; Dawal and Taha, 2007;

Guimarães et al., 2012) (Table 3).

Table 3 – Description the studies included in systematic review

Table 3 (cont.) – Description the studies included in systematic review




The participants of the studies were of the both genders, in working-age (18-65 years),

with samples ranging from 11 to 957 workers, and with 4 to 25 workstations.

The indicators and tools used to evaluate the outcomes varied widely. The majority of

the studies used tools that had either dichotomous (yes or no) or Likert (0-10) scales

responses. The Likert scale was evaluated immediately after job rotation occurred or in a

follow up period of between one and three and a half years. While six studies proposed job

rotation schedules using equations or mathematic algorithm, which proved be able of to

generate the best job rotation solution (Asensio-Cuesta et al., 2012b; Asensio-Cuesta et al.,

2012a; Carnahan et al., 2000; Comper and Padula, 2014; Diego-Mas et al., 2009; Frazer et al.,

2003; Tharmmaphornphilas and Norman, 2007a) (Table 3).

Overall it appears that the evidence about job rotation is mixed. One study with good

quality had a positive results job rotation (Roquelaure et al., 1997). Of the six studies with fair

quality, three of these were positive (Dawal et al., 2009; Dawal and Taha, 2007; Guimarães et

al., 2012), two negative evidence (K. Fredriksson et al., 2001; Sato and Coury, 2009) and one

study the results were inconclusive evidence (Balogh et al., 2006). There were eight studies

with poor evidence and the results varied widely. For example, two studies found that job

rotation did not influence absence from work by sick leave amount (Sato and Coury, 2009)

and resulted in increase in reported musculoskeletal diseases (K. Fredriksson et al., 2001).

However, Guimarães et al. (2012) found positive findings in the reduction of the absence

from work, musculoskeletal disease and production losses in job rotation group. Even as

Roquelaure et al. (1997) found an association between low occurrences of carpal tunnel

syndrome in workplace where job rotation was implemented. Whereas other studies indicated

a positive increase in job satisfaction (Dawal et al., 2009; Dawal and Taha, 2007; Guimarães

et al., 2012). Others studies did not direct its conclusions about job rotation effects (Asensio-

Cuesta et al., 2012b; Asensio-Cuesta et al., 2012a; Carnahan et al., 2000; Diego-Mas et al.,

2009; Filus and Okimorto, 2012; Frazer et al., 2003; Tharmmaphornphilas and Norman,

2007a).

3.3 Parameters for the organization and implementation of job rotation schedules

The parameter used to create job rotation schedules varied. These parameters included

biomechanical exposure to physical risk factors (thirteen studies) (Asensio-Cuesta et al.,

2012b; Asensio-Cuesta et al., 2012a; Balogh et al., 2006; Carnahan et al., 2000; Comper and

Padula, 2014; Diego-Mas et al., 2009; Filus and Okimorto, 2012; Frazer et al., 2003;


2009; Tharmmaphornphilas and Norman, 2007a), organizational (twelve studies) (Asensio-

Cuesta et al., 2012b; Asensio-Cuesta et al., 2012a; Carnahan et al., 2000; Comper and Padula,

2014; Dawal et al., 2009; Dawal and Taha, 2007; Diego-Mas et al., 2009; Filus and Okimorto,

2012; Frazer et al., 2003; Guimarães et al., 2012; K. Fredriksson et al., 2001; Roquelaure et

al., 1997), cognitive (seven studies) (Asensio-Cuesta et al., 2012b; Comper and Padula, 2014;

Dawal et al., 2009; Dawal and Taha, 2007; Diego-Mas et al., 2009; Guimarães et al., 2012;

Sato and Coury, 2009). Psychosocial factors were described in five studies (Asensio-Cuesta et

al., 2012b; Dawal et al., 2009; Dawal and Taha, 2007; Guimarães et al., 2012; K. Fredriksson

et al., 2001). Environmental factors and safety aspects were also mentioned in five studies

((Asensio-Cuesta et al., 2012b; Asensio-Cuesta et al., 2012a; Diego-Mas et al., 2009;

Guimarães et al., 2012; Roquelaure et al., 1997). Only tree studies (Asensio-Cuesta et al.,

2012b; Diego-Mas et al., 2009; Guimarães et al., 2012) used all the parameters mentioned

previously. In most of the articles, after the parameter description, the author indicated that

rotation occurred between different biomechanical risk level (Asensio-Cuesta et al., 2012b;

Asensio-Cuesta et al., 2012a; Balogh et al., 2006; Comper and Padula, 2014; Diego-Mas et

al., 2009; Filus and Okimorto, 2012; Frazer et al., 2003; Guimarães et al., 2012; Roquelaure et

al., 1997; Sato and Coury, 2009; Tharmmaphornphilas and Norman, 2007a) or complexity

levels of task or both (Diego-Mas et al., 2009; Filus and Okimorto, 2012; Guimarães et al.,

2012).

Most of the studies describing job rotation schedules were organized in four rotations

per day, being three after two hours long and one after an hour of work (Asensio-Cuesta et al.,

2012b; Comper and Padula, 2014; Diego-Mas et al., 2009; Guimarães et al., 2012). There are

studies that proposed definition of job rotation or evaluated the best time between each

schedule, considering aspects such as fatigue (Filus and Okimorto, 2012), characteristics of

production and tasks (Asensio-Cuesta et al., 2012a; Carnahan et al., 2000;

Tharmmaphornphilas and Norman, 2007a) or did not report the time between each job

rotation (Dawal et al., 2009; Dawal and Taha, 2007; Roquelaure et al., 1997).

Table 4- Strategies to implement job rotation schedules

Biomechanical Organizational Cognitive/Mental Others

Comper (2014) Posture at work: sitting,

kneeling, standing, walking

Movements analysis:

amplitude and frequency

Exposure risk level: low,

moderate and high

Use of tools and machines

Percentage of occupation in

work cycles

Mental Capacities:

autonomy

Not reported Each 2 hours Ergonomic analysis

Quick Exposure Check

(QEC)

Rapid Entire Body

Assessment (REBA)

Rotation between

different biomechanical

risk level - low,

moderate and high risk

Not reported (1) The level of exposure

intensity

(2) Predominantly posture at

work

(3) The main physical demand

(material handling, repetition of

movements, static posture)

(4) Body regions of higher

overhead

(5) Production’s specificities

Filus (2012) Muscular overload: apply

for different muscular group

activity

Perception about

complexity of tasks: easy,

moderate or dificult

Not Reported Not reported One, two and three hours

(1ª week - Each one

hour; 2ª week -Each 2

hours; 3ª week - Each 3

hours)

Not Reported Rotation between

different complexity

levels of task - easy,

moderate and difficult

Not reported (1) Biomechanics analysis

(2) Staff engaged

Asensio-Cuesta

(2012a)

Posture: awkward

Movements of analysis:

amplitude and frequency,

stereotypy,

lack of postural variation,

inadequate recovery

periods

Force : application of force

Turn duration; Breaks Not Reported Safety aspects:

Protection use of gloves

Enviromental factors:

exposure to cold

Four job rotations per

day. 1st, 2nd and 3 th (2

hours) and 4th (1 hour).

Computational Software

Genetic Algorithm (GA)

and OCRA method

Rotation between


risk level - low,


Not reported (1) Know the performance the

tasks by the worker

(2) Biomechanical risk level

(3) Ergonomic staffs: analysis

continues to observe sensitive

changes

Asensio-Cuesta

(2012b)

Posture at work: standing,

climbing,

Movements of analysis:

frequency, limitations to

perfomance, coordinating

movements

Force: exerting force

standing still and movement

Competence Criteria

writing, using computer

(mouse and keyboard),

driving vehicles, hearing,

know the company

strategies and policies and

adaptability and self-control,

learning skills, engagement

and responsibility,

willingness)

Cognitive Demand:

hearing, locating direction

of sound, seeing from a

distance

Psychosocial factors:

enthusiasm, meticulous

and rigorous work

Safety aspects: working

at heights


day. 1st, 2nd and 3 th (2


ECRot model -


Genetic Algorithm (GA).

(39 criteria were used to

characterize the workers

and jobs included in the

rotation schedules)

Rotation between


risk level - low,


Not reported (1) Know the performance the

tasks by the worker

(2) Minimization of fatigue

accumulation

(3) Competence and Physical

skills demanded by the tasks

Guimarães (2012) Biomecachical risk

factors

Workstation:

characteristics, layout, task

content, task design

Issues related to the

organizational culture.

Complexity of the task:

easy, moderate or dificult

Mental Capacities and

Cognitive Demand: rate

of learning; learning

Curve (LC) to each task


participative approach

(company and workers),

preferences of workers

Safety: risk of task

Enviromental factor:

general physical aspects.

Each 2 hours (beginning)

to Time decided by

workers (each 1.5 hours)

after implementation.

Learning Curve (LC) modeling ; Macroergonomic Work Analysis (MA)Rotation between

different complexity

levels of task - easy,

moderate and difficult

Training (1) Training for all workers (3.5

years) (2) After initial criteria’s

the workers themselves

established the job rotation.

Priorities to organize job

rotationImplementationAuthors/Year

Parameters/Demands Protocol and Intervals

(Time )Tools to risk analysis Schedule

Table 4 (Cont.) – Strategies to organize and implement job rotation schedules


Diego-Mas (2009) Posture at work: standing,

sitting, walking, climbing,

Movements analysis:


Physical capacities:

coordination movements

Force: applying force in

movement (transport, push,

pull)

General capacities:

driving vehicles, working at

height, writing, speaking,

using keyboard and mouse

Mental Capacities:

complex decisions,

responsibility,

cooperation with others,

attention/concentration/a

utonomy

Cognitive demands:

long distance vision,

color vision, hearing

locating the direction,

tactile sensivity,

smelling/tasting,

Safety aspects:

personal protection

equipment,

Enviromental factor:

confined places


day. 1st, 2nd and 3th (2


Organization Job rotation

schedule according risk

factors.



DPI-ASEPEYO genetic

algorithm;

MORE software – to

obtain the maximum

flexibility.

Rotation between

different movements

demands and work

content

Not reported (1) Biomechanics criteria

(2) Mental capacities

(3) Communication capacities

Sato (2009) Posture at work: standing,

sitting or walking

Not reported Mental Capacitites:

Intensity of the work

(heavy or light).

Cognitive demands:

high for sorting products

or low for exclusively

manual activities.

Not reported Job rotation schedule to

modify

the exposure patterns.

Each one hour.

Ergonomic Workplace

Analysis (EWA)

Rotation between

different cognitive and

physical demands -

high physical/low

cognitive demands and

high cognitive /low

physical demands

Not reported (1) Biomechanical demands

(2) Mental and Cognitive

demands

Dawal (2009) Not reported Job organization: job

rotation, work method,

training, problems solving

and goal setting

Mental Capacities:

power decisions, self-

regulation and worker

autonomy.


job satisfaction

Not reported Not reported Not reported

(Dawal,2007) Not reported Job organization: job

rotation, work method,

training, problems solving

and goal setting

Mental Capacities: job-

related decisions, self-

regulation and worker

autonomy


job satisfaction

Not reported Not reported

Tharmmaphornphilas

(2007)

Task caracteristics: Lifting

weight (kg). Lifting

frequency (cm). Lifting

height (cm). Horizontal

lifting distance (cm). Lifting

rate (lifts/minute)

Not reported Not Reported Not Reported Different schedule of

work to different

scenarios

Each one hour ( workers

perform tasks during the

first 50 minutes and relax

during the last 10

minutes)

Mathematical models

deterministic and

stochastic problems for

Minimizing the maximum

number of lost days

(StochMinMaxDays) and

Minimizing the total

number of lost days

(StochMinTot-Days).

Rotation considering the

subtask demand

Not reported (1) Lifting weight (kg)

(2) Lifting rate (lifts/minute)

(3) Lifting distance (cm)

Balogh (2006) Posture at work

Moviment analysis:

amplitude and frenquency

Muscular overload :

muscle activity

Not reported Not Reported Not Reported All operators - Five work

tasks per day.

Not reported Not reported Not reported Not reported

ImplementationPriorities to organize job

rotationAuthors/Year

Parameters/Demands Protocol and Intervals

(Time )Tools to risk analysis Schedule

Table 4 (Cont.) – Strategies to organize and implement job rotation schedules


Frazer (2003) Physical demands:

workload posture and

moviments

Anthropometric criterial:

height and weight.

Force: magnitude hand grip

force.

Task caracteristics: lifting

limit

Cycle time Not Reported Sociodemographic

caracteristics: gender

Two jobs Computational software -

Biomechanical model:

estimate the moment of

force and reaction forces

for the major body joints

(low back).

Not reported Not reported (1) Peak L4/L5 shear force and

moment cumulated.

Fredriksson (2001)

Moviment analysis:


Physical demands:

workload regarding

strenuous postures and

movements

Job demands: Workpace,

workload

Competence Criterial:

demand for skill and

creativity

Opportunities to influence

work: Monotony

Not Reported Psychosocial factors:

support at work,

occupational pride

stimulation from work

oportunities to influence

work

Four times per day. Not reported Rotation successively

implementation of job

rotation - production team

decision

Training (1) Training operators (Six-month

training)

(2) Recruited person

Carnahan (2000) Physical demands: lifting

capacities, spent to

performing others tasks. .

Organizational demands

and

time spent performing other

tasks.

Complexity of the taks:

easy or difficult)

Not Reported Sociodemographic

caracteristics: gender

One or two hours –

dependents of the

characteristics of task

(easy or difficult).



Rotation according to

gender capacity groups

Not reported (1) Lifting weight (kg), Lifting rate

(lifts/minute), Lifting distance

(cm)

(2) Gender and lifting capacity

Roquelaure (1997) Moviment analysis:

frenquency

Task caracteristics:

pinching, gripping,

screwing, pulling, pushing,

lifting, turning, Force:

Production caracteristics

Use of tools

Work pace

Capactities to decision

Not Reported Enviromental factor:

cold and vibration

Not reported Checklist based on the

RULA method

Not reported Not reported (1) Two or more workstations to

considerer job rotation;

(2) Biomechanical risk factors

Authors/YearParameters/Demands Protocol and Intervals

(Time )Tools to risk analysis Schedule Implementation

Priorities to organize job

rotation

37

There were six studies that used mathematic equations and software to organize the

job rotation schedules, four studies organized the job rotation from the parameters previously

defined often with the support of the production teams, health, and safety (Asensio-Cuesta et

al., 2012b; Asensio-Cuesta et al., 2012a; Carnahan et al., 2000; Diego-Mas et al., 2009; Fraser

and Hvolby, 2010; Tharmmaphornphilas and Norman, 2007a). Job rotations were

implemented with the training of workers in two studies and there were not reported job

rotation implementation in other studies. The criteria and parameters used to organize and

implement job rotation schedule are reported in Table 4.

4. Discussion

The objectives of this systematic review were to identify the effect of job rotation on

1) specific work-related musculoskeletal issues; 2) exposure to known risk factors,

specifically physical risk factors; and, 3) psychosocial risk factors. Additionally, this review

aimed to determine how job rotation should be designed. The results were inconclusive with

regard to the effectiveness of job rotation. Although there was a great variability of

parameters described, in most of the studies, biomechanical and organizational factors were

used to define the job rotation schedules. There was however some similarity in the

scheduling, as job rotation shifts tended to vary between one or two hours in each study.

The mixed results about job rotation effectiveness can be explained by the variability

in different outcomes measures and results of the non-randomized clinical trials, proposed by

Guimarães et al. (2012) and Fredriksson et al. (2001). Guimarães et. al (2012) reported

positive results associated with job rotation, while Fredriksson et al. (2001) determined that

job rotation did not contributed to MSD reduction. Probably, this is due to different

understanding of the meaning of the job rotation as strategy for the prevention and control of

MSDs.

Fredriksson et al. (2001) used job rotation as a way to fragment tasks and increase

the production rate, as if breaking up tasks could reduce this burden for workers. They

evaluated workers of the car-body-sealing department at an automobile assembly plant and

compared those who worked on car in line out system (control group) with workers job

rotation schedules in line system whose each workers did part of the job (Intervention group).

The line system with job rotation had worse outcomes than line out system, as the physical

workload and MSDs increased significantly (p<0.05). Furthermore, workers reported lower

job control and consequently, were less stimulated. Guimarães et al. (2012) prioritized the

38

acquisition of skills by workers to job rotation schedules and evaluated job rotation effects

after 3.5 years indicated a significant reduction in work-related musculoskeletal injuries,

absenteeism, turnover, rework, and spoilage between those with the job-rotation scheduling

and those without it.

In addition, Roquelaure et al. (1997) found a positive association between the carpal

tunnel syndrome and workers who perform job rotation. However, the design of this study

(case-control) it has the potential for risk of bias, especially because the data was collected

retrospectively, making difficult to assess exposure. Similarly, Balogh et al. (2006) and Sato

and Coury (2009) proposed another study design (cross-sectional) that allow not confirm the

effectiveness of job rotation. Furthermore, these studies are not described job rotation with

main intervention strategy that generates various confounding the measured outcomes.

There were three studies reported positive results job rotation implementation with

increasing job satisfaction (Dawal and Taha, 2007; Guimarães et al., 2012). Even though,

these results are not directly related to the prevention or control of musculoskeletal disorders,

surely they influence the acceptance of job rotation, which is also associated with health

outcomes (Rissen et al., 2002). Dawal et al. (2009) and Dawal and Taha (2007) studies

evaluated of effect various organizational factors (work methods, training, job rotation)

showing positive job rotation correlation with job satisfaction independent age and the

approval of 70% of workers. Guimarães et al. (2012) observed that after training works to job

rotation implement the workers were more confidence to develop a task and showed more

satisfaction with work. These findings shown the greater involvement and worker training to

accomplish the task were positive and improve job satisfaction, although the studies

methodological quality were fair with cross-sectional design.

We found a great number of parameters for organization and implementation job

rotation. Biomechanical and organizational parameters were the most used and, especially,

include aspects related to posture, movement frequency, level of exposure and complexity

level of task. These findings were consistent with the ergonomic job rotation purposes of

alternating tasks of the different complexities and biomechanical requests (Guimarães et al.,

2012; Mathiassen, 2006). On the other hand, interestingly, we found a large number of studies

that proposed the job rotation of tasks with high repeatability and no possibility of variation of

production rate and movements (Asensio-Cuesta et al., 2012b; Asensio-Cuesta et al., 2012a;

Balogh et al., 2006; Diego-Mas et al., 2009; Filus and Okimorto, 2012; Fraser and Hvolby,

2010; K. Fredriksson et al., 2001; Roquelaure et al., 1997). In these cases, the job rotation

may well not reduce overload and increase worker stress. The implementation of job rotation

39

in tasks with high repeatability seems to meet the problem caused by the fragmented work on

production lines. This result could be related to the fact that many companies implemented

job rotation programs with production, cost, and quality in mind, not employee health (Azizi

and Liang, 2013; Costa and Miralles, 2009; Michalos et al., 2010; Moreira and Costa, 2013).

Another related explanation could be that companies implemented job rotation program with

the goal of expanding the skills or from a production rearrangement (Balogh et al., 2006;


2009).

Regarding the job rotation schedules, the most studies indicated mathematical

equations or algorithms to create proposals for switching between tasks, for situations where

the working day is 8 hours, with intervals of one or two hours (Asensio-Cuesta et al., 2012b;

Carnahan et al., 2000; Comper and Padula, 2014; Diego-Mas et al., 2009; Guimarães et al.,

2012; K. Fredriksson et al., 2001; Sato and Coury, 2009). The reasons for the choice for these

intervals were not mentioned in almost all studies. Only Guimarães et al. (2012) described

that a job rotation schedule of every two hours rather than an average one and a half hour was

better for that group. Job rotation was started four time daily each two hours until the workers

acquire skill with for a large number of tasks, then the time average between each job rotation

was 1hour and 30 minutes, and the tasks could be decided by the worker himself (Guimarães

et al., 2012).

In fact, based on this review, we cannot recommend a standard job rotation schedule.

This is because, in general, the studies reported little about the strategies used to perform the

rotation, indicating that job rotation was likely not implemented as a preventive measure for

MSD reduction, rather, for a need for engineering the flexibility of workers. Many of the

equations proposed to define the job rotation schedules relay on a variety of parameters [e.g

posture and movements, mental and cognitive capacities, strategies and policies, learning

skills, responsibility, long distance vision, color vision, hearing locating the direction, writing,

speaking. However, none of the studies describe how they determined that these were the

important factors. Thus, much remains to be studied on these equations to integrate theory and

practice and thereby contribute to decision making in the job rotation implementation.

Job rotation, despite being an important intervention, and founded upon the principles

of ergonomics, was found to be more often used to meet a need for production and for the

training of multifunctional workers. There were many studies identified in this review that

were determined to be of poor or fair methodological quality due to insufficient level of detail

regarding the study population, sample size, power, randomization, blinding, dropout rate,

40

intervention and outcomes. The problem of the poor quality of the studies can possibly be

explained by the difficulty in implementing new health and safety programs in worksites.

Dempsey (2007) described on the benefits of progress and barriers encountered in the design

of research on the effectiveness of ergonomic interventions to prevent MSDs and found that

there was a negative of bias to the evidence of the studies. This study confirms that there is

weak evidence of the effectiveness of job rotation reduce overload and prevent

musculoskeletal disorders in manufacturing industries.

Further studies are required to better methodological quality, although it is necessary

to consider alternative research designs (Schelvis et al., 2015), taking into account among

other factors the specificities of each manufacturing industry and the possibilities within the

differentials production organizations. In addition, identify facilitators or barriers in each

organizational level can contribute to job rotation planning and implementation (Leider et al.,

2015b).

Successful implantation of the job rotation programs depended on a number of

important factors, such as involvement and acceptance of managers, job characteristics,

production method, number of employees and the tasks involved the biomechanics of

exposure level. Thus, it is necessary to analyze the activities that will be part of job rotation,

sort your complexity, perform training (Guimaraes et al., 2012), and determine how long each

worker must remain in each tasks (Tharmmaphornphilas and Norman, 2007b) and meet these

requirements is important for positive results for the workers' health. In addition, we believe

that the scheduling should be selected based on the specifics of the job and individual

characteristics of the workers. Besides, we must not forget that industrial innovation,

adjustments of production and the very ergonomic improvements create different exposure

scenarios and difficult intervention studies (Dempsey, 2007).

5. Limitations

A limitation of this study relates to how the articles included in the review were

selected, as only information in the title and abstract were reviewed initially. The studies did

not follow clear criteria for description of the methods in this way was very difficult to find

the information, which often was in another part of the text. Some studies were excluded

because the results of different manufacturing industries were presented together which

prevented the analysis of information. Others did not present central tendency and dispersion

measurements or statistical analysis.

41

6. Conclusion

We found a few number of current studies on job rotation in manufacturing industries.

While most articles indicated in their goals that they would evaluate job rotation effect; this

was not the majority. Those that did evaluate the effect of the intervention often grouped the

effect with other organizational factors. Although same studies tried to provide support of the

benefits of job rotation, the methodological quality was often poor, and they had inappropriate

designs to assess outcomes. It was therefore not possible to conclude if job rotation was

effective to reduce musculoskeletal overload and disease prevention.

Acknowledgements

The National Counsel of Technological and Scientific Development (CNPq), Brazil

(473651/2013-0 and 249621/2013-4), is funding this study.

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63

Appendix 1

Quality Assessment of Controlled Intervention Studies

Criteria Yes No

Other

(CD, NR,

NA)*

1. Was the study described as randomized, a randomized trial, a

randomized clinical trial, or an RCT?

2. Was the method of randomization adequate (i.e., use of

randomly generated assignment)?

3. Was the treatment allocation concealed (so that assignments

could not be predicted)?

4. Were study participants and providers blinded to treatment group

assignment?

5. Were the people assessing the outcomes blinded to the

participants' group assignments?

6. Were the groups similar at baseline on important characteristics

that could affect outcomes (e.g., demographics, risk factors, co-

morbid conditions)?

7. Was the overall drop-out rate from the study at endpoint 20% or

lower of the number allocated to treatment?

8. Was the differential drop-out rate (between treatment groups) at

endpoint 15 percentage points or lower?

9. Was there high adherence to the intervention protocols for each

treatment group?

10. Were other interventions avoided or similar in the groups (e.g.,

similar background treatments)?

11. Were outcomes assessed using valid and reliable measures,

implemented consistently across all study participants?

12. Did the authors report that the sample size was sufficiently

large to be able to detect a difference in the main outcome between

groups with at least 80% power?

13. Were outcomes reported or subgroups analyzed prespecified

(i.e., identified before analyses were conducted)?

14. Were all randomized participants analyzed in the group to

which they were originally assigned, i.e., did they use an intention-

to-treat analysis?

Quality Rating (Good, Fair, or Poor) (see guidance)

Rater #1 initials:

Rater #2 initials:

Additional Comments (If POOR, please state why):

*CD, cannot determine; NA, not applicable; NR, not reported

Appendix 2

64

Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies

Criteria Yes No

Other

(CD, NR,

NA)*

1. Was the research question or objective in this paper clearly

stated?

2. Was the study population clearly specified and defined?

3. Was the participation rate of eligible persons at least 50%?

4. Were all the subjects selected or recruited from the same or

similar populations (including the same time period)? Were

inclusion and exclusion criteria for being in the study prespecified

and applied uniformly to all participants?

5. Was a sample size justification, power description, or variance

and effect estimates provided?

6. For the analyses in this paper, were the exposure(s) of interest

measured prior to the outcome(s) being measured?

7. Was the timeframe sufficient so that one could reasonably expect

to see an association between exposure and outcome if it existed?

8. For exposures that can vary in amount or level, did the study

examine different levels of the exposure as related to the outcome

(e.g., categories of exposure, or exposure measured as continuous

variable)?

9. Were the exposure measures (independent variables) clearly

defined, valid, reliable, and implemented consistently across all

study participants?

10. Was the exposure(s) assessed more than once over time?

11. Were the outcome measures (dependent variables) clearly

defined, valid, reliable, and implemented consistently across all

study participants?

12. Were the outcome assessors blinded to the exposure status of

participants?

13. Was loss to follow-up after baseline 20% or less?

14. Were key potential confounding variables measured and

adjusted statistically for their impact on the relationship between

exposure(s) and outcome(s)?


Rater #1 initials:

Rater #2 initials:


*CD, cannot determine; NA, not applicable; NR, not reportedAppendix 3

65

Quality Assessment of Case-Control Studies

Criteria Yes No

Other

(CD, NR,

NA)*

1. Was the research question or objective in this paper clearly stated

and appropriate?

2. Was the study population clearly specified and defined?

3. Did the authors include a sample size justification?

4. Were controls selected or recruited from the same or similar

population that gave rise to the cases (including the same

timeframe)?

5. Were the definitions, inclusion and exclusion criteria, algorithms

or processes used to identify or select cases and controls valid,

reliable, and implemented consistently across all study

participants?

6. Were the cases clearly defined and differentiated from controls?

7. If less than 100 percent of eligible cases and/or controls were

selected for the study, were the cases and/or controls randomly

selected from those eligible?

8. Was there use of concurrent controls?

9. Were the investigators able to confirm that the exposure/risk

occurred prior to the development of the condition or event that

defined a participant as a case?

10. Were the measures of exposure/risk clearly defined, valid,

reliable, and implemented consistently (including the same time

period) across all study participants?

11. Were the assessors of exposure/risk blinded to the case or

control status of participants?

12. Were key potential confounding variables measured and

adjusted statistically in the analyses? If matching was used, did the

investigators account for matching during study analysis?


Rater #1 initials:

Rater #2 initials:


*CD, cannot determine; NA, not applicable; NR, not reported

Appendix 5

66

MEDLINE

1. (company or companies).mp

2. department$. ti,ab.

3. employee*.mp

4. employer*.mp

5.employer?.ti,ab.

6.employ*.mp.

7. (factory or factories).ti,ab.

8. firm?.ti.ab.

9.industr*.mp.

10. laborer?.ti,ab.

11.labourer?.ti,ab.

12. manager?.ti,ab.

13. operator*.mp.

14. operator?.ti,ab.

15. organization*.mp

16.organi#ations$.ti,ab.

17.occupation*.mp

18. team?.ti,ab.

19. work*.mp

20. work environment.mp

21. worker*.mp.

22. worker?.ti,ab.

23. workplace.mp.

24. workstation.mp.

25. or/1-24

67

26.ergonomics.mp.

27.ergonomic$.ti,ab

28. 26 or 27.

29.job organization.mp.

30.job transfer$.ti,ab.

31.job rotation.mp

32. job design

33. (job adj design).ti,ab

34. (multi adj criteria$).ti,ab

35. multi task/

36. multiskilling/

37. schedule$ adj2 production).ti,ab

38. schedule production.mp

39. personnel rotation

40. (personnel adj rotation).ti,ab.

41. task allocation.mp

42. task rotation.mp

43. task performance.mp

44.(task? adj2 modifi$).ti,ab.

45. organizational learning.mp

46. work schedule.mp

47. work rotation.mp.

48. or/ 29 - 47

49. 28 and 48

50. cost effectiveness analysis.mp

51. management of individual?.ti,ab.

52. organisational polic$.ti,ab.

68

53. return$ to work.ti,ab.

54. stay$ at work .ti,ab.

55. (job adj2 modifi$).ti,ab.

56. (promot$ adj2 recovery).ti,ab.

57. work intervention

58.(work$ adj2 intervention?).ti,ab.

59. absenteeism.mp

60. accidents, occupational.mp

61. claim$.ti,ab

62. cumulative trauma disorder.mp

63. disability management program$.ti,ab.

64. early intervention?.ti,ab.

65. employee satisfaction survey?.ti,ab.

66. employee satisfaction.ti,ab.

67. engagement.ti,ab.

68. functional capacity assessment?.ti,ab.

69. health protection.mp

70. health risk management.ti,ab.

71. healthy workplace strateg$.ti,ab.

72. healthy workplace.mp

73. job accommodation.mp

74. job adaptation/

75. job control.ti,ab.

76. job demand/

77. job performance/

78. job satisfaction/

79. job turnover.ti,ab.

69

80. joint labor management initiative?.ti,ab.

81. long term disability benefit?.ti,ab.

82. long-term disabilit$.ti,ab.

83. lost time.ti,ab.

84. lost workday?.ti,ab.

85. musculoskeletal injuries/

86. musculoskeletal pain/

87. musculoskeletal system/

88. labo?r force participation.ti,ab.

89. musculoskeletal disorders.mp

90. occupational disorders.mp

91. occupational exposure.mp

92. occupational health.mp

93. outcome assessment.mp

94. performance indicators.mp.

95. performance management.ti,ab.

96. periodic medical examination/

97. personnel management.mp

98.or/ 50-97

99. 25 and 49 and 98

CINAHL

S1. compan*

S2. department*

S3. employee

S4. employer

S5.employ*.

70

S6. (factory or factories).

S7.industr*.

S8. manager*

S9. operator*

S10. organization*

S11.occupation*

S12. work*

S13. work environment

S14. workplace.

S15. workstation

S16. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15

S17.ergonomics.mp.

S18.job organization.mp.

S19.job transfer*

S20.job rotation

S21. job design

S22. multi task

S23. multiskilling

S24. schedule production

S25. personnel rotation

S26. (personnel adj rotation).ti,ab.

S27. task allocation.mp

S28. task rotation.mp

S29. task performance.mp

S30.(task? adj2 modifi$).ti,ab.

S31. organizational learning.mp

S32. work schedule.mp

71

S33. work rotation.mp.

S34. 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or

32 or 33

S35. 16 and 34

S36. cost effectiveness analysis.mp

S37. management of individual?.ti,ab.

S38. organisational polic$.ti,ab.

S39. return$ to work.ti,ab.

S40. stay$ at work .ti,ab.

S41. (job adj2 modifi$).ti,ab.

S42. (promot$ adj2 recovery).ti,ab.

S43. work intervention

S44.(work$ adj2 intervention?).ti,ab.

S45. absenteeism.mp

S46. accidents, occupational.mp

S47. claim$.ti,ab

S48. cumulative trauma disorder.mp

S49. disability management program$.ti,ab.

S50. early intervention?.ti,ab.

S51. employee satisfaction survey?.ti,ab.

S52. employee satisfaction.ti,ab.

S53. engagement.ti,ab.

S54.functional capacity assessment?.ti,ab.

S55. health protection.mp

S56. health risk management.ti,ab.

S57. healthy workplace strateg$.ti,ab.

S58. healthy workplace.mp

S59. job accommodation.mp

72

S60. job adaptation/

S61. job control.ti,ab.

S62. job demand/

S63. job performance/

S64. job satisfaction/

S65. job turnover.ti,ab.

S66. joint labor management initiative?.ti,ab.

S67. long term disability benefit?.ti,ab.

S68. long-term disabilit$.ti,ab.

S69. lost time.ti,ab.

S70. lost workday?.ti,ab.

S71. musculoskeletal injuries/

S72. musculoskeletal pain/

S73. musculoskeletal system/

S74. labo?r force participation.ti,ab.

S75. musculoskeletal disorders.mp

S76. occupational disorders.mp

S77. occupational exposure.mp

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86

CAPÍTULO 4

ARTIGO 3

The Effectiveness of Job Rotation to Prevent and Control Work-

Related Musculoskeletal Disorders: A Cluster Randomized

Clinical Trial

Será submetido à revista: The Journal of the American Medical

Association (JAMA)

87

THE EFFECTIVENESS OF JOB ROTATION TO PREVENT AND CONTROL

WORK-RELATED MUSCULOSKELETAL DISORDERS: A CLUSTER

RANDOMIZED CLINICAL TRIAL

Maria Luiza Caires Comper, MS1,2

*, Jack Tigh Dennerlein, PhD3,4

, Rosimeire Simprini

Padula, PhD**

1. Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo,

São Paulo, Brazil.

2. Discipline of Physical Therapy, União Metropolitana de Ensino e Cultura, Itabuna, Brazil.

3.Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston,

Massachusetts, United States.

4. Department of Physical Therapy, Movement, and Rehabilitation Sciences Bouvé College

of Health Sciences, Northeastern University, Boston, Massachusetts, United States.

*Corresponding authors

Maria Luiza Caires Comper

E-mail: *[email protected]; **[email protected]

Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, Rua

Cesario Galeno 475, 03071-000 - São Paulo-SP, Brazil.

Tel.: +55 11 21781564



88

ABSTRACT

IMPORTANCE: Several reasons justify the use of job rotation as an organizational strategy

for industrial production lines. It is used for increasing performance, autonomy and flexibility

of workers and alternate continuous exposure to risk factors for musculoskeletal disorders.

However, the effectiveness of job rotation to prevent and control musculoskeletal complaints

has limited evidence.

OBJECTIVE: To investigate the effectiveness of job rotation to prevent musculoskeletal

disorders in industrial manufacturing workers.

DESIGN, SETTING AND PARTICIPANTS: This is a 1-year cluster randomized

controlled trial with blinded assessor. Production departments of a Brazilian textile industry

were randomized into intervention and control groups.

INTERVENTIONS: Both groups received ergonomics training. Intervention group

performed job rotation program.

OUTCOMES AND MEASURES: The primary outcome measure was number of working

hours lost due to sick leave measure (hours) in 3-months follow-up. Secondary outcomes

were measured at baseline and 12-month follow-up and included: musculoskeletal symptoms

(Yes/No), job factors for musculoskeletal pain and disorders (0-10), psychosocial factors and

fatigue(0-100), and general health (0-100) and productivity (0-10).

RESULTS: The final sample included 2 departments into intervention group (N=266) and 2

into control group (N=255). After 12 months, the job rotation program did not significantly

change its effect on number of working hours lost due to the sick leave caused by

musculoskeletal injury. There was also no difference in favor of the intervention group (MD -

5.6 hours, 95% CI -25.0 to 13.8) at 12-month follow-up. There were also no differences

between groups for the secondary outcomes (P > 0.05).

CONCLUSION: The job rotation program was no more effective than the control group in

preventing musculoskeletal disorders in industrial workers.

Trial registration: NCT01979731, November 3, 2013

Keywords: Job design; Physical workload; Industrial Workers

Introduction

Work-related musculoskeletal disorders (WMSDs) are a large problem for workers

and companies because it affects the work ability causing negative effects in quality of life

and productivity and increasing number of days of lost work1. Therefore, achieving effective

interventions for control and management of WMSDs is imperative to reduce the risk of

workers developing this disorders2. The interventions often recommended are: ergonomic

design, participatory ergonomic3, ergonomic guidelines and adjustments, rest breaks at work

and job rotation4.

Job rotation is an organizational strategy widely used in production lines with

manufacturing processes5-8

, with the goal of increasing performance, autonomy and flexibility

of workers9,10

and mitigate continuous exposure to risk factors for musculoskeletal

disorders4,11

. The premise is that the alternation of biomechanical exposure provides rest

period for a muscle group while other groups are being recruited12

. As a result, it reduces

cumulative biomechanical overload in a specific part of body4. Job rotation is recommended

to tasks with repeatability of movements6,13

, load lifting12

or awkward and static postures14,15

.

It is used for reduces monotony and boredom16

, to decrease absenteeism17

, increases worker’s

autonomy, flexibility and satisfaction18

, and reduces stress19

. Moreover, the variability of

tasks included in the job rotation favors workers who have temporary or permanent

disabilities20

.

Job rotation effectiveness depends on several criteria and parameters used to planning

and implementation of this intervention21

. It is recommended to identify the mainly demands;

determine biomechanical exposure levels; create the job rotation schedule; and, train all

workers to each job/task22

. However, there is no consensus about which parameters should be

used for create the Job Rotation23

. Instead of this, the studies that have evaluated the effects of

job rotation described a great variability of parameters, what explains, in part, the conflicting

and inconsistent results11

. There are different purposes for job rotation implementation being

study design and methodological quality other possible explanations for the limited

evidence11,23

. Regarding to the purposes, the job rotation has been used to prioritize the needs

of production, as part of a lean production system and total quality7 or to prevent

musculoskeletal disorders4,11

. Until now, there is no studies whose methodological quality is

and design are adequate to endorse the effectiveness, since most of the studies are cross-

sectional or longitudinal with fair to poor methodological quality23

. As a result, there is a lack

of evidence to support the use of JRP with the purpose to prevent work-related

musculoskeletal diseases.

Therefore, it is concluded that there is a clear and important need for well-designed

studies on the function of rotation has been planned with the purpose to reduce biomechanical

overload. The aim of this study was to evaluate the effect of a JRP with specific criteria to

reduce the biomechanical overload and in the prevention of musculoskeletal disorders in

industrial textile workers.

The hypothesis this study, considering the literature findings, the guidelines,

regulatory standards, and experts in the field is that variability and shorter exposure level to

biomechanical risk caused by job rotation resulting in fewer hours lost due to sick leave for

intervention group. Furthermore, we believe that job rotation would be able to reduce the

occurrence of musculoskeletal symptoms, to improve the perception of workers face the

ergonomic and psychosocial risk factors and increase productivity.

Methods

Design, Setting and Participants

This study was a prospectively registered at ClinicalTrials.Gov (NCT01979731),

cluster randomized controlled trial, with blinded assessment of outcomes. The procedures and

consent form were approved by the Research Ethics Committee of Cidade de São Paulo

University (protocol no. 18170313.5.0000.0064). It was conducted at a large Brazilian textile

industry (N=3000 workers). Four production departments of a large Brazilian textile industry

(Finishing Socks, Finishing Underwear, Sewing Socks and Sewing Underwear) meet the

inclusion criteria and were included in the study. These departments had production layouts

organized into lines or cells, whose rhythm was not determined by machines and allowing

switching between tasks with different biomechanical demands and levels of risk for

musculoskeletal pain and disorders; and never had performed job rotation before.

Sewing departments (453 workers) was composed of cutting and sewing machines. It

was characterized by prolonged sitting, repetitive movements in wrists, hands and fingers, and

static muscular overload on the spine and shoulders. The finishing departments (504 workers)

were composed of industrial machines or tables, or a combination of both. The standing

position was preferably adopted because the majority of the activities required material

handling or small displacements between workstations. Repetitive movements in the upper

limbs were also common, especially in shoulders, wrists and hands. The departments were

grouped by similar demands and level of exposure to risk factors for musculoskeletal pain and

disorders (Finishing Socks + Finishing Underwear and Sewing Socks + Sewing Underwear)

and randomly assigned to intervention and control groups, before baseline measurements24

.

The methods of the study were more detailed in a published protocol24

. However,

some changes beyond the control of researchers occurred during the execution of the study.

One month after having started the study the managers concluded the time spend by workers

in answering the questionnaires was too much and harmed the organization dynamics. So, the

follow-up interval for secondary outcomes could be collected every three months as expected

and previously agreed by the managers, being collected only at baseline and after 12-months

intervention. There was no change to the primary outcome follow-up.

Description of Interventions

Intervention and Control Groups

In both groups studied, workers received ergonomic training taught by a

physiotherapist/ergonomist. The training was conducted on a single day over 4 hours, with

lectures on ergonomic risk factors and their influence on the development of musculoskeletal

symptoms, improvements and adaptations for workstations, work postures and preventive

exercise25

.

Job Rotation Program (Intervention Group)

Procedure to create and implement the Job Rotation Program (JRP)

All departments that received JRP were deployed in three phases. Firstly (June 2013-

September 2013), one of the researchers, with 10-years expertise in ergonomics, arranged a

meeting with the production managers to explain the study proposal and procedures and to

define the sectors that filled the eligibility criteria. After discussing about the characteristics

and peculiarities of the tasks performed in the production departments, the production

managers and researches concluded that only 4 production sectors were sectors with

production lines whose rhythm is not determined by machines and allowing switching

between tasks with different biomechanical demands and levels of risk for musculoskeletal

pain and disorders. Then, managers described the characteristics and particularities of these

sectors, the required level of training and possible difficulties in carrying out the job rotation.

In the second phase (October 2013 - January 2014), an ergonomic analysis of the tasks

performed in the productive sectors was carried out. The purpose of this analysis was to

identify: (1) the main physical demand (materials handling, repetitive movements, static

posture); (2) the predominantly posture adopted to perform the task (sitting, kneeling,

standing, walking); (3) the body regions parts of higher overhead (shoulders, elbows, wrists,

hands, spine); and (4) the intensity of exposure level (low, moderate, high or very high).

The intensity of exposure level were assessed using Quick Exposure Check (QEC)26,27

and Rapid Entire Body Assessment (REBA)28

, which assess the main risk factors for

musculoskeletal disorders (frequency of movement, postures, amount of weight handled,

manual force, visual demands, presence of vibration, work pace, and stress)26,29

and level of

task complexity, classified as either easy or difficult according task characteristics from

cognitive demands and learning time17

. All this information was used for classification of

tasks and definition of job rotation schedule. The workers were trained for two months.

Finally, the job rotation schedule implementation occurred in the third phase

(February 2014 – February 2015). One of the researchers monitored it daily, in the first two

months.

Job Rotation Schedule

Job Rotation Schedule was created according to the following priority criteria: (1)

tasks with low or moderate exposure risk level was alternated with high and very high, (2)

tasks that require a predominantly standing posture was alternate with tasks that require a

sitting posture, (3) handling tasks alternated with tasks requiring repetition of movements, and

(4) tasks alternate body regions of higher overhead. The completion of the rotation took place

at intervals of 2 hours because this interval time is compatible with a lower lactic acid30

and

has been consensus in several other studies23

.

Sample size calculation

The study was designed to detect a between-group difference reduction of 10%

working hours lost due to sick leave by musculoskeletal injuries (M Group International

Classification of Diseases, ICD-10). That means, the groups would have a difference of 100

hours, with a standard deviation of 250 hours. A statistical power of 80%, an alpha of 5%, and

a possible sample loss of up to 15% were also considered. Therefore, a total of 232

participants were required.

Randomization

The randomization was performed by an independent researcher, who was not

involved in recruitment and assessment, using a computer-generated randomization

(www.randomizer.org) with random numbers to define groups. All workers within the

participating production sectors were allowed to participate in the study and those who

agreed, signed a consent form before entering the study.

Outcome measures

Despite the intervention had been applied in the production sectors, the outcomes were

evaluated at an individual level.

Primary outcome

The increase of costs caused by sickness absence is a major problem for industrial

organizations31,32

. That is why the primary outcome measure was absence from work due to

sick leave, assessed by the number of working hours lost due to symptom or disease of the

musculoskeletal system and connective tissue (M Group International Classification of

Diseases, ICD-10).

The industry where the study was conducted registered daily the occurrence of

workers who had sick note. The record was done by the human resources sector and includes

information about the medical certificate's reason (ICD-10) and the number of days lost. All

information has been obtained by electronic report, extracted by a person who was unaware of

the study and group participants.

Secondary outcomes

The secondary outcome measures were musculoskeletal symptoms, risk factors for

musculoskeletal pain and disorders, psychosocial factors and fatigue, general health and

productivity.

Musculoskeletal symptoms (pain, tingling, or numbness) was assessed using the

Nordic Musculoskeletal Questionnaire (QNSO). The workers answered yes or no in relation

to musculoskeletal symptoms they have experienced during the past 12 months33

. Data shows

prevalence of WMSDs in the neck, shoulders, elbows, hands, upper back, low back, hips,

knees and feet.

Risk factors for musculoskeletal pain and disorders were assessed by the perception of

workers against risk factors that may contribute to the development of musculoskeletal

complaints through the Job Factors Questionnaire. This instrument presents a descriptive list

of 15 risk factors that should be classified on a scale of zero to ten, indicating the worker’s

perception about how much each factor contributed to the occurrence of WMSDs symptoms,

with zero meaning "no problem" and ten indicating the "largest possible problem"34

.

The perception of workers against psychosocial factors and stress, resulting in fatigue

induced by work, were evaluated through the Scale of Need for Recovery35

. This Likert scale

has 11 questions and possible answers of numbers up to 4 (0=never, 1=sometimes, 2=often,

and 3=always). The answer “always” indicates an unfavorable situation and receives 3 scores,

with the exception of item 4, which features reverse scoring. The total score is obtained by

summing the final, transformed by rule of three direct, on a scale of 0 (minimum) to 100

(maximum). Higher scores indicate greater frequency and intensity of symptoms related to

fatigue and stress and, consequently, greater need for recovery36

.

Overall health status and quality of life was assessed by the World Health

Organization Quality of Life scale, abbreviated version (WHOQOL-BREF)36,37

. This self-

reported instrument contains 26 questions, divided into four areas: social, psychological,

physical, and environment. Each domain consists of questions whose answer scores range

between 1 and 536,37

. The averages of the issues and domains scores are converted to a scale

of 0 to 10. Higher score indicates better quality of life38

.

A single item WHO General Health Questionnaire and Performance at Work [27]

measured productivity. Participants assigned a score (0–10) for their labor productivity. The

cost-effectiveness of interventions was calculated according to the cost effectiveness

incremental. For this, we considered the cost required to conduct ergonomic guidelines and

cost guidelines in conjunction with job rotation. These values are divided by the time lost

from work1.

The primary outcome was assessed at baseline and three-months follow-up. The

secondary outcomes were assessed at baseline and 12-months after the randomization, by a

blinded assessor. In the study, it was impossible to blind workers and ergonomists because of

the nature of the intervention used. To test blinding, after assessment of outcomes, the

worker’s assessment researcher and noted his opinion as to the type of intervention received

by workers.

Statistical Analysis

The statistical analysis was conducted on an intention-to-treat basis which is

participants were analyzed in the groups to which they were randomly allocated. The Shapiro-

Wilk test was used to assess the normality of the data. Descriptive statistics were used in the

analysis of characteristics of the participants. The chi-square test was used to evaluate the

blinding of the assessor by comparing the randomization codes and the evaluator. The

difference between the groups and their respective confidence intervals was calculated using

linear mixed models by using group, time and group-versus-time interaction terms [30]. The

within group difference was calculated using the Student paired t test for dependent samples.

The difference between the groups for nominal data was calculated using the McNemar's test.

The significance level is 5%. The statistical program SPSS 23.0 was used for all analyses.

Results

Participants Flow and Loss to follow-up

A total of 10 departments (N=1987 workers) were assessed for eligibility and four

departments (N=581 workers) were included. All workers were invited to participate, but 136

1 Cost-effectiveness data will not appear on this version but will be included for article

submission.

declined. Besides that, prior to randomization, 330 workers were dismissal due to business

reasons. At the final, after randomization, two departments (N=266 workers) were allocated

to the intervention group and two (N=225) to the control group. Figure 1 presents a summary

of enrollment, intervention allocation, follow-up and data analysis of departments and

participant in this trial.

At 12 month-intervention, workers were dismissal due to business reasons (N=136

workers) and 32 workers from JRP not finalized the intervention by determination of the

company's management. Then, the loss to follow-up on the primary and secondary outcomes

measure was 25.2% in the intervention group and 26.2% in the control group. Anyway, the

total of participants meets the sample calculation, which required the 232 workers.

Figure 1 – Participant’s enrollment, intervention allocation, follow-up, and data analysis.

Sociodemographic characteristics

The participants were predominantly female (77.8%) and had a mean time in the

company of 50 months. The mean number of working hours lost due to sick leave by

musculoskeletal injuries was 27.2. At baseline, no meaningful differences between the groups

for demographic characteristics were found. The demographic characteristics of the workers

in the intervention group and the control group are presented in Table 1.

Table 1- Sociodemographic variables for both groups (control and intervention) and all

workers (n=491)

Effects on the number of working hours lost due to sick leave by musculoskeletal injuries

At 12-month follow-up both groups showed a progressive increase in the number of

working hours lost due to sick leave by musculoskeletal injuries. No significant differences

between groups were observed for any follow-up. In the within-group comparison, the results

Table 1- Sociodemographic variables for both groups (control and intervention) and all

workers (n=491)

Variable Control

(N=225)

Intervention

(N=266)

Sex

Male 30 (13.3)

72 (21.1)

Female 195 (86.7)

194 (72.9)

Age (years) 32.5 (9.0)

28.4 (7.8)

Marital status

Single 158 (70.2)

211 (79.3)

Married 60 (26.7)

49 (18.4)

Divorced 2 (0.9)

0 (0.0)

Widowed 3 (1.3)

3 (1.1)

Not mentioned 2 (0.9)

3 (1.1)

Education status

Illiterate 17 (7.6)

12 (4.5)

Elementary degree 67 (29.8)

58 (21.8)

High School 130 (57.8)

183 (68.8)

University 8 (3.6)

11 (4.1)

Not mentioned 3 (1.3)

2 (0.8)

Employment time in the company (months)

56.9 (44.3)

49.6 (43.2)

showed a significant difference for the 6-month, 9-month and 12-month follow-up at the

intervention group and for the 9-month and 12-month follow-up at the control group (Table

2).

Table 2 – Description of primary outcome for both groups (control and job rotation) and all

workers (n=491)

Effects on musculoskeletal symptoms

The table 3 shows that the prevalence of workers with symptoms of pain or

musculoskeletal discomfort were decreased in almost body regions for both groups after 12

months of intervention in both groups. There was a significant reduction of symptoms only

for wrists and hands symptoms.

Primary

Outcome

Groups Unadjusted Mean (SD)

Unadjusted Within-Group

Differences (Baseline minus Follow-up)

Between-Group

Adjusted Mean

Differences

(Intervention

minus Control) Intervention

(N=266)

Control

(N=225)

Intervention

(N=266)

Control

(N=225)

Absence from work due to sick leave (Hrs.)

Baseline 20.3 (54.8)

34.2 (79.4)

3 month

a 27.1 (57.34)

34.0 (62.6)

0.3

(-0.1 to 0.6)

0.0

(-0.5 to 0.5)

7.0

(-12.4 to 26.4)

6 months

a 37.2 (103.7)

43.5 (73.5)

0.7b

(0.2 to 1.2)

0.4

(-0.1 to 0.9)

7.6

(-11.8 to 27.0)

9 months

a 45.7 (107.2)

49.3 (99.0)

1.1b

(0.5 to 1.6)

0.7b

(0.0 to 1.2)

10.3

(-9.1 to 29.7)

12 months

a 49.2 (110.5)

68.7 (157.7)

1.2

(0.3 to 0.7) 1.4

b

(0.6 to 2.2) -5.6

(-25.0 to 13.8)

Hrs. = Hours a Missing data: Intervention group (n=67) and Control group (n=59)

b Significant difference within groups (P < 0.05)

Table 3 - Description of musculoskeletal symptoms outcome for both groups (control and job

rotation) and all workers (n=491)

a Significant difference within groups (P < 0.05)

Effects of self-perception on the musculoskeletal pain risk factors, fatigue and psychosocial

factors and general health

Table 4 shows the intervention effects on the four outcomes. Three of these are related

to the effects that JRP on self-perception the musculoskeletal pain risk factors, fatigue and

psychosocial risk factors and general health at the baseline and after 12 months of

intervention. The results showed that JPR was not able to improve the self-perception workers

to the risks factors and their general health. Rather, workers had a worse perception for all

results. On the contrary, workers had a worse perception for all these outcomes. No

significant differences between groups were observed for any outcome. However, in the

within-groups comparison, there was a significant difference for almost all outcomes for both

groups. The only exception was the perception about psychosocial factors and fatigue in the

intervention group.

Secondary Outcomes

Groups Frequency

P-Value Month 0

Month 12

Intervention (N=266)

Control (N=225)

Intervention (N=266)

Control (N=225)

Musculoskeletal symptoms (%)

Neck

98 (36.8)

89 (39.6)

70 (26.3)

73 (32.4) 0.29

Shoulders 145 (54.5)

120 (53.3)

112 (42.1)

97 (43.1) 0.11

Upper back 120 (45.1)

94 (41.8)

77 (28.9)

83 (36.9) 0.85

Elbows

18 (6.8)

18 (8.0)

12 (4.5)

23 (10.2) 0.12

Wrists/Hands 101 (38.0)

88 (39.1)

79 (29.7)

79 (35.1) 0.04a

Low back 104 (39.1)

84 (37.3)

65 (24.4)

76 (33.8) 0.73

Hips/Thighs 30 (11.3)

36 (16.0)

22 (8.3)

28 (12.4) 0.65

Knees

50 (18.8)

42 (18.7)

36 (13.5)

48 (21.3) 0.19

Ankles/Fit 75 (28.2)

55 (24.4)

43 (16.2)

58 (25.8) 0.52

100

Table 4 – Description of secondary outcomes for both groups (control and job rotation) and all workers (n=491)

Secondary

Outcomes

Groups Unadjusted Mean (SD)

Unadjusted Within-Group

Differences

(Baseline minus Follow-up)a

Between-Group

Adjusted Mean

Differences

(Intervention

minus Control) Month 0

Month 12

Intervention

(N=266)

Control

(N=225)

Intervention

(N=266)

Control

(N=225)

Intervention

(N=266)

Control

(N=225)

Musculoskeletal pain

risk factors (0-150) 72.5 (37.9)

77.9 (36.3)

84.1 (33.1)

85.6 (33.9)

11.9b

(6.2 to 17.6)

6.3b

(1.0 to 11.7)

4.6

(-3.1 to 12.2)

Psychosocial factors

and fatigue (0-100) 38.7 (18.1)

37.3 (18.4)

39.3 (18.0)

40.2 (18.2)

1.9

(-0.6 to 4.8)

2.7b

(0.1 to 5.3) -1.5

(-4.9 to 2.0)

General health (0-100)

Physical domain

64.2 (15.5)

62.3 (15.5)

58.0 (13.6)

58.2 (14.3)

-7.0b

(-9.7 to -4.2)

-4.3b

(-6.9 to -1.7) -2.2

(-5.8 to 1.4)

Psychological

domain 68.7 (15.5)

67.8 (15.2)

64.5 (12.3)

63.5 (12.5)

-5.1

b

(-7.6 to -2.6)

-4.5b

(-6.8 to -2.2) -0.8

(-3.4 to 3.2)

Social domain

68.4 (18.8)

66.0 (20.0)

61.7 (15.6)

60.9 (14.9)

-6.7b

(-9.9 to -3.4)

-5.6b

(-8.9 to -3.4) -1.5

(-5.9 to 2.9)

Environmental

domain 50.2 (13.7)

46.3 (15.2)

46.1 (10.4)

42.2 (13.4)

-4.4

b

(-6.9 to -1.9)

-3.8b

(-6.3 to -1.2) -0.7

(-3.5 to 3.3)

Productivity (0-10) 8.3 (1.6)

8.4 (1.6)

8.1 (1.7)

7.5 (2.6)

-0.4b

(-0.1 to -0.6)

-0.9b

(-1.3 to -0.6) 0.99

(-0.85 to 1.05)

a Missing data: Intervention group (n=67) and Control group (n=59)

b Significant difference within groups (P < 0.05)

Effects on productivity

Table 4 also shows the effects of JRP on productivity. During the 12 months, there

was a decreased of productivity with a significant difference for both groups, in the within-

group comparison. However, in between group, no significant differences were found.

Blinding

The evaluator blinding was confirmed by the number of hits to intervention group

(58.3 %) and to control group (50.1 %) (p >0.05).

Discussion

This study is the first randomized controlled trial that aimed evaluates the

effectiveness of JRP designed to prevent and control work-related musculoskeletal disorders.

It was conducted with a large population of industrial workers during twelve months. After

the intervention, the job rotation was not more effective than the control group for any of the

assessed outcomes. This means that it was not effective in reducing the number of working

hours lost due to sick leave by musculoskeletal injuries; decreasing the prevalence of

musculoskeletal symptoms; and, improve self-perception musculoskeletal pain risk factors,

psychosocial risk factors and productivity. Only the prevalence of wrists and hands

musculoskeletal symptoms had a significant improvement after de job rotation.

Two recent systematic reviews11,23

had already demonstrated two important findings

that compromised the confirmation job rotation effectiveness. Firstly, the quality of evidence

is very low39

because no randomized clinical trial has been found and most studies have

longitudinal and cross-sectional study designs with methodological quality varying between

fair and poor23

. Secondly, the reviews concluded that the effectiveness of job rotation is

conflicting and inconsistent11,23

. These studies have found positive and negative results for job

rotation effects on WMSD. For example, Guimarães et al. (2012)40

showed a significant

reduction in the occurrence musculoskeletal injuries, absenteeism, turnover, rework, and

spoilage in workers who performed job rotation for 3.5 years. Roquelaure et al. (1997)41

found a positive association between job rotation and the carpal tunnel syndrome prevention.

But, on the contrary, Fredriksson et al. (2001)42

founded that physical workload and

frequency of WMSD’s occurrence increased significantly in the group of workers who

performed job rotation schedules in line system 42

. Similar results were found by Balogh et al.

(2006)43

and Sato and Coury (2009)17

. However, these studies the job rotation was not the

main intervention assessed, resulting in various confounders to the measured outcomes.

Unlikely the studies mentioned our study was adequately planned job rotation for

mitigating continuous exposure to risk factors for musculoskeletal disorders40,44

. Therefore,

we evaluated the job characteristics and production method and measured the biomechanical

and psychosocial risk exposure level in all tasks included; we created the schedule based on

criteria and parameters suggested by the scientific literature; managers was involved and

accepted to realize the JRT; all workers were trained; and, the tasks were easy to perform.

Also, it is important to mention that the JRP deployment process has been well accepted by

managers and by most workers during the 12 months specified in the study design. Perhaps

it's due to the fact that this industry has an ergonomics program for 10 years. This program

includes ergonomic design, participatory ergonomic, ergonomic guidelines and adjustments

and rest breaks at work. Despite all this, our trial failed to demonstrate the effectiveness of the

JRP in reducing the number of working hours lost due to sick leave by musculoskeletal

injuries.

There are several possible explanations for our findings. The first explanation is

related to the primary outcome, which was chosen due to the cost caused by WMSDs and its

contribution to decision-making regarding the management of safety and health strategies. We

assumed that, if the job rotation were effective for to prevent and to control WMSDs, it would

be able to reduce the number of working hours lost due to sick leave. However, it seems that

this outcome may not be the most appropriate to measure the health effects promoted by

ergonomic strategies used for promoting work variability17,45,46

, because its represents a long-

term indicator. Furthermore, the number of hours of work lost due to sick leave may be

related to the worsening of musculoskeletal symptoms requiring greater number of days/hours

of absence from work1,47

. The second explanation is that the industry where the study was

conducted had never done job rotation before. Maybe, for this reason, the workers were not

interested in developing new skills, which is an important prerogative for the success of this

intervention48

. Another explanation is that the inclusion of tasks with high risk level in the

JRP may limit the positive effects of variability generated by this intervention.

The only outcome for which the job rotation had a significant improvement was the

prevalence of wrists and hands musculoskeletal symptoms. This finding agrees with

Roquelaure et al. (1997)41

and Klussmann et al.(2008)49

. The last one shows that the

prevalence of symptoms of the hand/wrist was influenced by frequency of job rotation49

. In

our study, this result may be related to the fact that the wrists/hands have had less exposure

time and greater variability, obtained by rotating between lifting and gripping or repetitive

tasks. Other body regions, such as the neck, shoulder and low back, had no adequate rest,

because its muscles were kept in static muscular contractions, although of rotation between

the different tasks.

Our study have several strengths of methodological issues, such as: cluster RCT study

design and its statistical power; recruitment of a large population as well as the inclusion of

workers from diverse task with different workloads; randomization by department which

minimizes possible contamination between workers from the intervention and control groups;

use of standardized questionnaires to measure study outcomes; and blinding of assessor. As a

result, our study findings can be generalized for work settings with characteristics similar to

those of this study (i.e. manufacturing industries with production layouts organized into lines

or cells, whose rhythm was not determined by machines and allowing switching between

tasks with different biomechanical demands and levels of risk for musculoskeletal pain and

disorders).

A limitation of this study was the changes in the trial design that was beyond the

control of researchers. Managers did not allow that the secondary outcomes follow-up were

collected every three months as described in the research project due to the time spend by

workers in answering the questionnaires. Then, the secondary outcomes follow-up was

collected only at the baseline and after the 12-month intervention. Managers also did not

allowed two of the tasks included in the intervention group (N = 32 employees) continue in

the study, since the workers boycotted the rotation, causing a negative effect on productivity.

However, all the statistical analysis was conducted on an intention-to-treat basis. This ensures

that non-compliance, protocol deviations, withdrawal, and anything that happens after

randomization may influence the results, resulting in overoptimistic estimates of the efficacy

of an intervention50

.

Another limitation was the considerable loss to follow-up rates on secondary

outcomes found after 12 months. Unfortunately, loss to follow-up is a common problem

among prevention studies51

, particularly in industrial settings where determinations of

organizations may affect the study conduction52

. However, our loss to follow-up rates was

<30%, not affecting the ability to draw firm conclusions53

. Besides, the total of participants

exceeds the number of participants defined by sample size calculation.

In fact, based on the results of this study, it can be concluded that there was no

advantage of using JRP to decrease the number of working hours lost due to musculoskeletal

symptom or disease and to prevent and control musculoskeletal disorders. These results

challenge the theory that job rotation is a good organizational strategy for to prevent and

control musculoskeletal complaints, particularly, in work settings whose exposure level

cannot be lowered due to the characteristics of the job or through physical measures4.

However, it is needed to take care in translating the results to all manufacturing industries. It

is necessary to consider the specifics of the job, settings and organization preferences and

necessities. In practice, it is up to managers and occupational health professionals who

provide occupational health services in different companies decide about the use of job

rotation. For example, in this textile industry, the managers decided to continue performing

the job rotation, even after being informed of the results. They understand that the results of

this intervention were positive in many aspects, as the development of workers with multi-

tasking skills, monotony and boredom reduction and good acceptance of Labor Inspection

Organs.

Conclusion

After 12 months, the results of this large cluster randomized clinical trial showed that

job rotation was not more effective than the control group into decrease the number of

working hours lost due to musculoskeletal symptom or disease and to prevent and control

musculoskeletal disorders.

Other Information

Registration

This trial was prospectively registered at ClinicalTrials.gov, number NCT01979731,

in November 3, 2013

Protocol

The methods of the study were more detailed in a published protocol, available with

full text of this article at BMC Musculoskeletal Disorders24

.

Funding

This study is supported by the National Counsel of Technological and Scientific

Development (CNPq), Brazil (473651/2013-0). The founders had no interference in any step

of this trial.

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113

CAPÍTULO 5

Desdobramentos do Estudo – Lições Aprendidas

Execução do projeto de pesquisa

A fase inicial do projeto de pesquisa, cujos métodos foram apresentados no capítulo 2,

teve início no período de junho a setembro de 2013. Neste momento, foram organizadas

diversas reuniões com os gestores de produção, incluindo: gerente, coordenadores,

supervisores e líderes de produção. O objetivo destas reuniões foi apresentar a proposta do

estudo e os métodos de implantação do rodízio, e com base nestas informações, definir os

setores que poderiam participar do estudo. Dentre os setores de produção da indústria têxtil

em questão, apenas 4 atendiam aos critérios de inclusão do estudo, ou seja, eram setores com

linhas de produção cujo ritmo não é determinado por máquinas o que permitiam a alternância

entre tarefas de diferentes solicitações biomecânicas e níveis de exposição. Uma vez definido

isto, os gestores explicaram aos pesquisadores quais eram as especificidades de cada tarefa; as

metas de produção; a autonomia de cada operação (técnicas, uso de máquinas, equipamentos

e ferramentas, e ritmo de trabalho); e, o nível de treinamento necessário para aptidão do

trabalhador.

Em seguida, realizou-se uma análise biomecânica com o objetivo de identificar: (1) a

principal demanda física (manuseio de materiais, repetição de movimentos, postura estática);

(2) a postura predominantemente adotada para a realização da tarefa (sentada, ajoelhada, em

pé, andando); (3) as regiões corporais de maior sobrecarga (ombros, cotovelos, punhos, mãos,

coluna); e, (4) o nível de intensidade da exposição (baixo, moderado, alto ou muito alto). O

nível de intensidade da exposição ao risco biomecânico foi avaliado pelos instrumentos

QEC1, REBA

2.

Todas as informações fornecidas pelos gestores e os resultados das análises

ergonômicas foram utilizados para construção da escala de rodízio. A proposta final desta

escala foi apresentada aos gestores juntamente com um plano de trabalho a ser cumprido na

implantação e acompanhamento do programa de rodízio de função. Por fim, mediante a

aprovação dos gerentes, o programa foi implantado em fevereiro de 2014.

114

Nos dois primeiros meses, o programa de rodízio de função foi monitorado

diariamente por um dos pesquisadores. Durante este período, algumas barreiras foram

encontradas. A primeira barreira decorreu da resistência dos trabalhadores alocados em duas

tarefas produtivas do setor de acabamento de peças sem costura (revisão de peças sem costura

e separação de peças sem costura – N=32 trabalhadores). De acordo com o planejamento

previsto, os trabalhadores destas tarefas fariam o rodízio entre si, alternando entre diferentes

níveis de exposição. Isto porque, a tarefa de revisão possuia alto nível de exposição ao risco

biomecânico em razão da postura e frequência de movimentos realizados, uso de força e

demanda visual requeridos para a inspeção da qualidade do produto. Já a tarefa separação de

peças (por tipo de produto, cor e tamanho) era caracterizada por movimentos neutros em

região de coluna cervical, membros superiores e coluna lombar, possuindo baixo nível de

exposição. Desta forma, considerando os diferentes riscos biomecânicos a alternância entre

estas tarefas seria perfeita devido a variabilidade existente entre elas. Contudo, os

trabalhadores da tarefa de separação não quiseram realizar a tarefa de revisão, o que refletiu

negativamente na produtividade. Com isso, os gerentes da indústria solicitaram que o

programa de rodízio fosse descontinuado para estas duas tarefas.

A segunda barreira encontrada foi a demissão coletiva de 330 trabalhadores decorrente

da redução de vendas e, consequentemente, da necessidade de redução de custos operacionais.

Felizmente, a demissão aconteceu no mês de novembro de 2013, antes da implantação do

programa de rodízio; e, apesar ter reduzido número da amostra inicial, não afetou o número

de trabalhadores previsto pelo cálculo amostral.

A necessidade de mudar o intervalo de seguimento para avaliar os desfechos

secundários foi a terceira e mais importante barreira. Isso porque, incialmente, o projeto

contemplava 4 coletas com intervalos de seguimentos de três meses. Porém, por decisão dos

gestores a coleta de dados aconteceu somente em dois momentos: no baseline e após os 12

meses de intervenção. Isto aconteceu em razão do tempo utilizado para responder os

questionários (em média 50-60 minutos), o que impactou na dinâmica dos setores de

produção.

Apesar destas ocorrências, o projeto foi cumprido sem problemas em todos os seus

objetivos. O programa de rodízio de função foi adequadamente planejado para promover a

redução da exposição contínua a fatores de risco que contribuem para o desenvolvimento de

distúrbios músculoesqueléticos. Para tanto, avaliamos as características do trabalho e dos

métodos de produção; mensuramos o nível de exposição ao risco biomecânico e psicossocial;

criamos uma escala de alternância com base em critérios e parâmetros sugeridos pela

115

literatura científica; envolvemos gestores e trabalhadores no processo de implantação e

treinamento das tarefas. A fácil implantação do programa de rodízio de função pode estar

relacionada ao fato de que esta indústria já possuia um programa de ergonomia há mais de 10

anos, que incluia: ergonomia participativa, intervenções fiísicas com redesenho dos postos de

trabalho, orientações ergonômicas e pausas no trabalho.

Lições Aprendidas

A fase de implantação do rodízio, nos fez compreender a necessidade de discutir

tópicos relevantes para o uso e compreenssão desta intervenção, apesar destes não terem sido

objetivos iniciais do estudo. Um deles se refere à tópicos relacionados a análise qualitativa

da implantação do rodízio de função na indústria têxtil. Isto porque identificamos na prática,

que a implantação da proposta (ideal), não é simples e pode não ser tão efetiva quanto vem

sendo descrita. Alguns obstáculos dificultam implantação, tais como: características da tarefa

(organização do trabalho, espaço físico e número de trabalhadores), convicção dos gestores

sobre a importância do rodízio e aceitação dos trabalhadores em realizá-lo

3. A aceitação de

alguns trabalhadores em alternar entre tarefas de baixo para alto risco foi uma das maiores

dificuldades encontradas em nosso estudo. Consideramos a necessidade de novos estudos que

incluam a análise de fatores individuais e características psicossociais dos trabalhadores como

parâmetro para o planejamento do rodízio.

Outro tópico importante a ser discutido são os métodos de análise do risco

biomecânico, utilizados para auxiliar no planejamento do rodízio e assegurar que a

alternância entre tarefas e níveis de exposição resultem na redução dos níveis de estresse

físico e cognitivo para os trabalhadores. Isto porque, o planejamento inadequado do rodízio

não só torna a intervenção ineficaz, como pode resultar em aumento dos níveis de exposição

(3). Assim, buscando compreender um pouco mais sobre este tópico, os pesquisadores

propuseram um estudo que teve como objetivo comparar dois métodos observacionais de

análise do risco biomecânico usados para definir uma proposta de rodízio de função. Os

resultados mostraram que: (1) a concordância entre os métodos REBA e QEC foi baixa,

quando se considera a pontuação total dos instrumentos; e, que (2) o uso de escores por

segmento corporal, além de outros critérios qualitativos podem ajudar nesta definição. Em

nosso ensaio clínico, a esclada de alternância de rodízio foi definida considerando a

pontuação dos instrumentos de análise de risco e alguns outros aspectos, tais como: ritmo de

116

trabalho, tempo de ciclo, principal demanda da tarefa e percepção de esforço, avaliados por

meio da expertise de um dos pesquisadores.

Referências

1. David G, Woods V, Li G, Buckle P. The development of the Quick Exposure Check

(QEC) for assessing exposure to risk factors for work-related musculoskeletal disorders. Appl

Ergon. . 2008; 39(1):57-69.

2. McAtamney L, Hignett S. REBA: a rapid entire body assessment method for

investigating work related musculoskeletal disorders. Proceedings of the Ergonomics Society

of Australia,1995.


implement multifunctional work teams in the Brazilian footwear sector. Appl Ergon. 2012;

43(3):541-7.

117

CAPÍTULO 6

Considerações Finais

Os objetivos desta tese de doutorado foram: (1) avaliar, por meio de uma revisão

sistemática, a eficácia do rodízio como estratégia de controle de risco e doenças e identificar

os parâmetros utilizados para organizar as escalas de rodízio nas indústrias de manufatura, (2)

reelaborar uma proposta de rodizio que pudesse evidenciar sua efetividade e, (3) avaliar, o

efeito do rodízio de função na prevenção dos distúrbios musculoesqueléticos em

trabalhadores industriais, por meio de um estudo clínico controlado e randomizado por

cluster.

Idealização da Revisão Sistemática, Conclusões e Desdobramentos

A revisão sistemática foi realizada após a idealização do projeto de pesquisa proposto

para avaliar a efetividade do rodízio de função como estratégia de prevenção aos distúrbios

musculoesqueléticos. A revisão, portanto, partiu da necessidade de compreender os critérios

utilizados para criação, as etapas de implantação, bem como escalas de organização do

rodízio, bem como analisar, mais criticamente, e concluir a razão para qual das divergências

dos efeitos. Isto porque, os artigos utilizados para construção do projeto de pesquisa não

respondiam a muitos dos questionamentos gerados. A revisão respondeu então, a alguns dos

questionamentos, mas há muito o que compreender ainda sobre os efeitos do rodízio de

função para prevenção e controle das lesões musculoesqueléticas.

Assim, o delineamento da revisão sistemática foi feito em outubro de 2013. A

proposta inicial foi a de realizar uma revisão ampla, incluindo as diferentes abordagens do

rodízio em diferentes populações de trabalhadores. No entanto, após algumas discussões,

optou-se por estudar o rodízio apenas em indústrias de manufatura, uma vez que este tem sido

o foco de pesquisa dos autores. Os objetivos da revisão sistemática foram: (1) sintetizar

evidências relacionadas a efetividade do rodízio de função utilizado como estratégia de

controle e prevenção dos distúrbios musculoesqueléticos e, (2) identificar os parâmetros

utilizados para organizar as escalas de rodízio nas indústrias de manufatura.

118

Os resultados gerais da revisão sistemática nos levaram a concluir que a evidência do

rodízio como estratégia para prevenção e controle de distúrbios osteomusculares é bastante

limitada, principalmente em razão da qualidade metodológica dos estudos e da ausência de

ensaios controlados randomizados. Se por um lado, este achado reforça a necessidade de

realização de novos estudos com melhor qualidade metodológica, por outro ele nos leva a

refletir sobre as dificuldades em realizar estudos que avaliam a efetividade de alguma

intervenção ergonômica em indústrias. Algumas destas dificuldades são: (1) a influência de

outros fatores da organização, que não podem ser controlados pelos pesquisadores, sobre a

intervenção testada; (2) barreiras para análises estatísticas, em razão do número de

trabalhadores por tarefa ou setor; (3) aceitação dos trabalhadores, dentre outros1,2

.

Outra conclusão é que os parâmetros para organização do rodizio descritos na revisão

sistemática possuem grande variabilidade de critérios, incluindo: postura e movimentos,

demandas cognitivas, estratégias e políticas da indústria, habilidades de aprendizagem,

responsabilidade, entre outros e são fortemente influenciados pelos modelos de produção,

organização e execução do rodízio de função. A maioria dos estudos utilizou ambos

parâmetros biomecânicos e organizacionais para a criação de suas escalas que contemplavam

intervalos de alternância variando entre uma ou duas horas. No entanto, nenhum deles

descrevem como a escala de rodízio foi planejada e o quanto estes parâmetros foram

determinantes para a efetividade do rodízio.

Por fim, pudemos observar que muitos estudos propõe a utilização de equações

matemáticas e algoritmos para auxiliar no planejamento das escalas de rodízio. Porém,

nenhuma destes foram testados na prática, o que dificulta a avaliação de sua efetividade.

Diante disso, verifica-se a necessidade de estudos que avaliem a efetividade das equações e

algoritmos para planejamento do rodízio de função. Este inclusive é um dos objetivos para

futuros estudos do nosso grupo, que prevê a elaboração e teste de uma equação matemática

que integre os critérios mencionados na literatura, incluindo principalmente a análise da

demanda específica de cada indústria e os fatores pessoais e psicossociais dos trabalhadores.

Diante do exposto, refletir sobre os resultados desta revisão e sobre as dificuldades

enfrentadas para se realizar um ensaio clínico em ambientes ocupacionais, nos faz

compreender a relevância do ensaio clínico conduzido por nosso grupo de pesquisa, para

avaliar a efetividade do rodízio de função em trabalhadores industriais. Nós acreditamos e

esperamos fortemente que seus resultados possam contribuir para a tomada de decisão de

gestores e profissionais de saúde e segurança que prestam serviços para as indústrias.

119

Idealização do Ensaio Clínico, Conclusões e Desdobramentos

O estudo do efeito do rodízio de função na prevenção dos distúrbios

musculoesqueléticos em trabalhadores industriais por meio de ensaio clinico “nasceu” de uma

demanda da indústria estudada. Esta indústria possui um programa de ergonomia que, há

algum tempo vinha recomendando sem sucesso, a utilização de rodízio de funções e pausas

programadas como estratégias para prevenção e controle dos distúrbios musculoesqueléticos.

A decisão da empresa por implantar o rodízio de função se deu em razão do número de

atestados decorrentes destes distúrbios e das frequentes solicitações dos órgãos fiscalizadores

do meio ambiente e trabalho. Diante desta oportunidade, um dos pesquisadores deste estudo

propôs que a implantação do programa de rodízio de função cumprisse todos os critérios

propostos pela literatura científica e fosse testado no desenho de um ensaio clínico controlado.

A proposta foi discutida, aceita e implantada em 2013/2014.

Durante a execução do estudo, enfrentamos algumas dificuldades, já descritas no

capítulo 5. Mas apesar disso, o projeto foi cumprido sem problemas em todos os seus

objetivos. Ao final, os resultados revelaram o programa de rodízio de função não foi mais

eficaz do que o grupo controle para a redução do número de horas de trabalho perdidos em

razão de atestados médicos por doenças musculoesqueléticas. Em outras palavras, o programa

de rodízio de função não foi efetivo em prevenir e controlar a ocorrência de distúrbios

osteomusculares em trabalhadores industriais. No entanto, é necessário tomar cuidado ao

transpor os resultados para todas as indústrias, pois é preciso considerar as particularidades de

cada organização.

O processo de implantação do rodízio na indústria têxtil fez com que os pesquisadores

considerassem a possibilidade de realizar futuros estudos que de identifiquem as melhores

ferramentas e critérios para análise de riscos biomecânicos, quando se deseja propor um

rodízio de função como estratégia de prevenção aos distúrbios musculoesqueléticos. Criar e

testar as propriedades de medida de um instrumento de análise de risco específica para o

planejamento do rodízio, coerente com as necessidades específicas de cada indústria, também

seria uma proposta interessante.

Os desdobramentos da fase de implantação do rodízio possibilitaram a produção

científica de dois resumos que apresentados em formato oral no congresso Work, Stress and

Health Conference in Atlanta, nos Estados Unidos, em maio de 2015. Além disso, a partir dos

120

resultados da implantação do rodízio, idealizou-se um projeto de iniciação científica. Este

projeto pretende verificar a concordância de parâmetros biomecânicos e organizacionais entre

um método observacional e uma equação de multicritérios desenvolvida por Diego-Mas et al3.

Referências

1. Dempsey PG. Effectiveness of ergonomics interventions to prevent musculoskeletal

disorders: Beware of what you ask. Int J Ind Ergon. 2007;37(2):169-73.

2. Schelvis RM, Oude HKM, Burdorf A, Blatter BM, Strijk JE, van der Beek AJ.

Evaluation of occupational health interventions using a randomized controlled trial:

challenges and alternative research designs. 2015;41(5):491-503.


multi-criteria genetic algorithm for the generation of job rotation schedules. Int J Ind Ergon.

2009; 39(1):23-33.

ANEXOS E APÊNDICES

www.unicid.edu.brR.

Cesário Galeno, 448/475

CEP- 03071 000 - São

Paulo SP

Tel: 55 11 2178 1200

DECLA RACÃ O

Declaro para os devidos fins que o Protocolo CAAE 18170313.5.0000.0064 -

"Efeitos do rodízio da tarefa na prevenção de distúrbios osteomusculares

relacionados ao trabalho: um estudo clínico randomizado por

agrupamento", pesquisadora responsável: Rosimeire Simprini Padula foi

submetido ao Comitê de Ética em Pesquisa da Universidade Cidade de São

Paulo - UNICID e aprovado no dia 12 de junho de 2013 .

São Paulo, 25 de março de 2014.

do CEP da Unicid

UNICID

Universidade Cidade de S.Paulo

http://www.unicid.edu.br/

APENDICE 1

TERMO DE CONSENTIMENTO LIVRE E ESCLARECIDO

Eu, ___________________________________________________________, abaixo

assinado, tendo sido devidamente esclarecido sobre os objetivos, riscos e demais condições

que envolverão minha participação no Projeto de Pesquisa intitulado EFEITOS DO

RODÍZIO DE FUNÇÃO NA PREVENÇÃO DE DISTÚRBIOS OSTEOMUSCULARES

RELACIONADOS AO TRABALHO: UM ESTUDO CLÍNICO RANDOMIZADO

POR AGRUPAMENTO, coordenado pela Profa. Dra. Rosimeire Simprini Padula, declaro

que tenho total conhecimento dos direitos e das condições que me foram apresentadas e

asseguras, as quais passo a descrever:

1. A garantia de ser informado e de ter respondida qualquer pergunta ou esclarecimento à

dúvidas sobre os procedimentos, objetivos, decorrências e riscos referentes às situações da

pesquisa a que serei submetido;

2. A garantia de que não serei pessoalmente identificado, a despeito da publicação dos dados

genéricos do estudo, e que terei resguardada minha privacidade;

3. A liberdade de deixar de participar do estudo, a qualquer momento, sem qualquer ônus ou

constrangimento;

4. A garantia de que me será prestada informação regular durante o estudo, ainda que esta

possa influenciar a minha decisão de nele permanecer;

Declaro, ainda, que estou ciente e concordante com todas as condições que me foram

apresentadas e que, livremente, manifesto a minha vontade em participar do projeto supra-

mencionado.

__(cidade)_,_____ de __________________ de ________.

___________________________/______________

Nome do participante (legível)/RG

______________________

Assinatura do pesquisador

Anexo 1

Questionário Nórdico para Sintomas Osteomusculares

ANEXO 2

Job Factors Questionnaire

ANEXO 3

Escala de Necessidade de Descanso

ANEXO 4

Whooquol- Bref

Instruções

Este questionário é sobre como você se sente a respeito de sua qualidade de vida, saúde e outras

áreas de sua vida. Por favor responda a todas as questões. Se você não tem certeza sobre que

resposta dar em uma questão, por favor, escolha entre as alternativas a que lhe parece mais

apropriada. Esta, muitas vezes, poderá ser sua primeira escolha.

Por favor, tenha em mente seus valores, aspirações, prazeres e preocupações. Nós estamos

perguntando o que você acha de sua vida, tomando como como referência as duas últimas

semanas. Por exemplo, pensando nas últimas duas semanas, uma questão poderia ser:

Nada Muito pouco Médio Muito Completamente

Você recebe dos

outros o apoio de

que necessita?

1 2 3 4 5

Você deve circular o número que melhor corresponde ao quanto você recebe dos outros o apoio

de que necessita nestas últimas duas semanas. Portanto, você deve circular o número 4 se você

recebeu "muito" apoio ou você deve circular o número 1 se você não recebeu "nada" de apoio.

nada Muito pouco Médio muito Completamente

Você recebe dos

outros o apoio de

que necessita?

1 2 3 5

Por favor, leia cada questão, veja o que você acha e circule no número e lhe parece a melhor resposta.

nº muito ruim Ruim nem ruim nem

boa boa muito boa

1 Como você avaliaria sua

qualidade de vida? 1 2 3 4 5

nº

muito

insatisfeito Insatisfeito

nem satisfeito

nem

insatisfeito

satisfeito muito

satisfeito

2 Quão satisfeito(a) você

está com a sua saúde? 1 2 3 4 5

As questões seguintes são sobre o quanto você tem sentido algumas coisas nas últimas duas semanas.

nº nada muito pouco mais ou menos bastante extremamente

3

Em que medida você

acha que sua dor (física)

impede você de fazer o

que você precisa?

1 2 3 4 5

4

O quanto você precisa de

algum tratamento médico

para levar sua vida

diária?

1 2 3 4 5

5 O quanto você aproveita

a vida? 1 2 3 4 5

6

Em que medida você

acha que a sua vida tem

sentido?

1 2 3 4 5

7 O quanto você consegue

se concentrar? 1 2 3 4 5

8 Quão seguro(a) você se

sente em sua vida diária? 1 2 3 4 5

9

Quão saudável é o seu

ambiente físico (clima,

barulho, poluição,

atrativos)?

1 2 3 4 5

As questões seguintes perguntam sobre quão completamente você tem sentido ou é capaz de fazer certas

coisas nestas últimas duas semanas.

nº nada

muito

pouco médio muito

completame

nte

10

Você tem energia

suficiente para seu dia-a-

dia?

1 2 3 4 5

11 Você é capaz de aceitar

sua aparência física? 1 2 3 4 5

12

Você tem dinheiro

suficiente para satisfazer

suas necessidades?

1 2 3 4 5

13

Quão disponíveis para

você estão as

informações que precisa

no seu dia-a-dia?

1 2 3 4 5

14

Em que medida você tem

oportunidades de

atividade de lazer?

1 2 3 4 5

As questões seguintes perguntam sobre quão bem ou satisfeito você se sentiu a respeito de vários aspectos de

sua vida nas últimas duas semanas.

nº muito ruim ruim nem ruim

bom muito bom nem bom

15 Quão bem você é capaz

de se locomover? 1 2 3 4 5

nº muito

insatisfeito Insatisfeito

nem satisfeito

nem

insatisfeito

satisfeito Muito

satisfeito


está com o seu sono? 1 2 3 4 5

17

Quão satisfeito(a) você

está com sua capacidade

de desempenhar as

atividades do seu dia-a-

dia?

1 2 3 4 5

18


está com sua capacidade

para o trabalho?

1 2 3 4 5


está consigo mesmo? 1 2 3 4 5

20


está com suas relações

pessoais (amigos,

parentes, conhecidos,

colegas)?

1 2 3 4 5

21


está com sua vida

sexual?

1 2 3 4 5

22


está com o apoio que

recebe dos amigos?

1 2 3 4 5

23


está com as condições do

local onde mora?

1 2 3 4 5

24


está com o seu acesso

aos serviços de saúde?

1 2 3 4 5

25


está com o seu meio de

transporte?

1 2 3 4 5

As questões seguintes referem-se a com que freqüência você sentiu ou experimentou certas coisas nas últimas

duas semanas.

nº nunca Algumas

vezes freqüentemente

muito

freqüentemente sempre

26

Com que freqüência você

tem sentimentos

negativos tais como mau

humor, desespero,

ansiedade, depressão?

1 2 3 4 5

ANEXO 6

Quick Exposure Check – Folha de avaliação

ANEXO 6 (Continuação)

Quick Exposure Check – Folha de pontuação

ANEXO 7

Rapid Entire Body Assessment – Folha de Avaliação


Rapid Entire Body Assessment – Folha de Avaliação (Continuação)


Rapid Entire Body Assessment – Folha de Pontuação


Rapid Entire Body Assessment – Folha de Pontuação (Continuação)

Anexo 8

Normas de Publicação do periódico Applied Ergonomics para o artigo apresentado no

Capítulo 4

Article structure

Subdivision - numbered sections

Divide your article into clearly defined and numbered sections. Subsections should be numbered 1.1 (then 1.1.1,

1.1.2, ...), 1.2, etc. (the abstract is not included in section numbering). Use this numbering also for internal cross-

referencing: do not just refer to 'the text'. Any subsection may be given a brief heading. Each heading should

appear on its own separate line.

Introduction

State the objectives of the work and provide an adequate background, avoiding a detailed literature survey or a

summary of the results.

Material and methods

Provide sufficient detail to allow the work to be reproduced. Methods already published should be indicated by a

reference: only relevant modifications should be described.

Theory/calculation

A Theory section should extend, not repeat, the background to the article already dealt with in the Introduction

and lay the foundation for further work. In contrast, a Calculation section represents a practical development

from a theoretical basis.

Results

Results should be clear and concise.

Discussion

This should explore the significance of the results of the work, not repeat them. A combined Results and

Discussion section is often appropriate. Avoid extensive citations and discussion of published literature.

Conclusions

The main conclusions of the study may be presented in a short Conclusions section, which may stand alone or

form a subsection of a Discussion or Results and Discussion section.

Appendices

If there is more than one appendix, they should be identified as A, B, etc. Formulae and equations in appendices

should be given separate numbering: Eq. (A.1), Eq. (A.2), etc.; in a subsequent appendix, Eq. (B.1) and so on.

Similarly for tables and figures: Table A.1; Fig. A.1, etc.

Essential title page information

• Title. Concise and informative. Titles are often used in information-retrieval systems. Avoid abbreviations and

formulae where possible.

• Author names and affiliations. Where the family name may be ambiguous (e.g., a double name), please indicate

this clearly. Present the authors' affiliation addresses (where the actual work was done) below the names.

Indicate all affiliations with a lower-case superscript letter immediately after the author's name and in front of

the appropriate address. Provide the full postal address of each affiliation, including the country name and, if

available, the e-mail address of each author.

• Corresponding author. Clearly indicate who will handle correspondence at all stages of refereeing and

publication, also post-publication. Ensure that telephone and fax numbers (with country and area code) are

provided in addition to the e-mail address and the complete postal address. Contact details must be kept up to

date by the corresponding author.

• Present/permanent address. If an author has moved since the work described in the article was done, or was

visiting at the time, a 'Present address' (or 'Permanent address') may be indicated as a footnote to that author's

name. The address at which the author actually did the work must be retained as the main, affiliation address.

Superscript Arabic numerals are used for such footnotes.

Abstract

A concise and factual abstract of between 100-150 words is required. The abstract should state briefly the

purpose of the research, the principal results and major conclusions. An abstract is often presented separately

from the article, so it must be able to stand alone. For this reason, References should be avoided, but if essential,

then cite the author(s) and year(s). Also, non-standard or uncommon abbreviations should be avoided, but if

essential they must be defined at their first mention in the abstract itself.

Graphical abstract

A Graphical abstract is optional and should summarize the contents of the article in a concise, pictorial form

designed to capture the attention of a wide readership online. Authors must provide images that clearly represent

the work described in the article. Graphical abstracts should be submitted as a separate file in the online

submission system. Image size: Please provide an image with a minimum of 531 × 1328 pixels (h × w) or

proportionally more. The image should be readable at a size of 5 × 13 cm using a regular screen resolution of 96

dpi. Preferred file types: TIFF, EPS, PDF or MS Office files. See http://www.elsevier.com/graphicalabstracts for

examples.

Authors can make use of Elsevier's free Graphical abstract check to ensure the best display of the research in

accordance with our technical requirements. 24-hour Graphical abstract check

Highlights

Highlights are mandatory for this journal. They consist of a short collection of bullet points that convey the core

findings of the article and should be submitted in a separate file in the online submission system. Please use

'Highlights' in the file name and include 3 to 5 bullet points (maximum 85 characters, including spaces, per bullet

point). See http://www.elsevier.com/highlights for examples.

Keywords

Immediately after the abstract, provide a maximum of 3 keywords, using American spelling and avoiding

general and plural terms and multiple concepts (avoid, for example, "and", "of"). Be sparing with abbreviations:

only abbreviations firmly established in the field may be eligible. These keywords will be used for indexing

purposes.

Abbreviations

Define abbreviations that are not standard in this field in a footnote to be placed on the first page of the article.

Such abbreviations that are unavoidable in the abstract must be defined at their first mention there, as well as in

the footnote. Ensure consistency of abbreviations throughout the article.

Acknowledgements

Collate acknowledgements in a separate section at the end of the article before the references and do not,

therefore, include them on the title page, as a footnote to the title or otherwise. List here those individuals who

provided help during the research (e.g., providing language help, writing assistance or proof reading the article,

etc.).

Math formulae

Present simple formulae in the line of normal text where possible and use the solidus (/) instead of a horizontal

line for small fractional terms, e.g., X/Y. In principle, variables are to be presented in italics. Powers of e are

often more conveniently denoted by exp. Number consecutively any equations that have to be displayed

separately from the text (if referred to explicitly in the text).

Footnotes

Footnotes should be used sparingly. Number them consecutively throughout the article, using superscript Arabic

numbers. Many wordprocessors build footnotes into the text, and this feature may be used. Should this not be the

case, indicate the position of footnotes in the text and present the footnotes themselves separately at the end of

the article. Do not include footnotes in the Reference list.

Table footnotes

Indicate each footnote in a table with a superscript lowercase letter.

Artwork

Electronic artwork

General points

• Make sure you use uniform lettering and sizing of your original artwork.

• Save text in illustrations as 'graphics' or enclose the font.

• Only use the following fonts in your illustrations: Arial, Courier, Times, Symbol.

• Number the illustrations according to their sequence in the text.

• Use a logical naming convention for your artwork files.

• Provide captions to illustrations separately.

• Produce images near to the desired size of the printed version.

• Submit each figure as a separate file.

A detailed guide on electronic artwork is available on our website:

http://www.elsevier.com/artworkinstructions

You are urged to visit this site; some excerpts from the detailed information are given here.

Formats

Regardless of the application used, when your electronic artwork is finalised, please 'save as' or convert the

images to one of the following formats (note the resolution requirements for line drawings, halftones, and

line/halftone combinations given below):

EPS: Vector drawings. Embed the font or save the text as 'graphics'.

TIFF: Color or grayscale photographs (halftones): always use a minimum of 300 dpi.

TIFF: Bitmapped line drawings: use a minimum of 1000 dpi.

TIFF: Combinations bitmapped line/half-tone (color or grayscale): a minimum of 500 dpi is required.

If your electronic artwork is created in a Microsoft Office application (Word, PowerPoint, Excel) then please

supply 'as is'.

Please do not:

• Supply files that are optimised for screen use (e.g., GIF, BMP, PICT, WPG); the resolution is too low;

• Supply files that are too low in resolution;

• Submit graphics that are disproportionately large for the content.

Color artwork

Please make sure that artwork files are in an acceptable format (TIFF, EPS or MS Office files) and with the

correct resolution. If, together with your accepted article, you submit usable color figures then Elsevier will

ensure, at no additional charge, that these figures will appear in color on the Web (e.g., ScienceDirect and other

sites) regardless of whether or not these illustrations are reproduced in color in the printed version. For color

reproduction in print, you will receive information regarding the costs from Elsevier after receipt of your

accepted article. Please indicate your preference for color: in print or on the Web only. For further information

on the preparation of electronic artwork, please see http://www.elsevier.com/artworkinstructions.

Please note: Because of technical complications which can arise by converting color figures to 'gray scale' (for

the printed version should you not opt for color in print) please submit in addition usable black and white

versions of all the color illustrations.

Figure captions

Ensure that each illustration has a caption. Supply captions separately, not attached to the figure. A caption

should comprise a brief title (not on the figure itself) and a description of the illustration. Keep text in the

illustrations themselves to a minimum but explain all symbols and abbreviations used.

Tables

Number tables consecutively in accordance with their appearance in the text. Place footnotes to tables below the

table body and indicate them with superscript lowercase letters. Avoid vertical rules. Be sparing in the use of

tables and ensure that the data presented in tables do not duplicate results described elsewhere in the article.

References

Citation in text

Please ensure that every reference cited in the text is also present in the reference list (and vice versa). Any

references cited in the abstract must be given in full. Unpublished results and personal communications are not

recommended in the reference list, but may be mentioned in the text. If these references are included in the

reference list they should follow the standard reference style of the journal and should include a substitution of

the publication date with either 'Unpublished results' or 'Personal communication' Citation of a reference as 'in

press' implies that the item has been accepted for publication.

Web references

As a minimum, the full URL should be given and the date when the reference was last accessed. Any further

information, if known (DOI, author names, dates, reference to a source publication, etc.), should also be given.

Web references can be listed separately (e.g., after the reference list) under a different heading if desired, or can

be included in the reference list.

References in a special issue

Please ensure that the words 'this issue' are added to any references in the list (and any citations in the text) to

other articles in the same Special Issue.

Reference management software

This journal has standard templates available in key reference management packages EndNote (

http://www.endnote.com/support/enstyles.asp) and Reference Manager (

http://refman.com/support/rmstyles.asp). Using plug-ins to wordprocessing packages, authors only need to select

the appropriate journal template when preparing their article and the list of references and citations to these will

be formatted according to the journal style which is described below.

Reference style

Text: All citations in the text should refer to:

1. Single author: the author's name (without initials, unless there is ambiguity) and the year of publication;

2. Two authors: both authors' names and the year of publication;

3. Three or more authors: first author's name followed by 'et al.' and the year of publication.

Citations may be made directly (or parenthetically). Groups of references should be listed first alphabetically,

then chronologically.

Examples: 'as demonstrated (Allan, 2000a, 2000b, 1999; Allan and Jones, 1999). Kramer et al. (2010) have

recently shown ....'

List: References should be arranged first alphabetically and then further sorted chronologically if necessary.

More than one reference from the same author(s) in the same year must be identified by the letters 'a', 'b', 'c', etc.,

placed after the year of publication.

Examples:

Reference to a journal publication:

Van der Geer, J., Hanraads, J.A.J., Lupton, R.A., 2010. The art of writing a scientific article. J. Sci. Commun.

163, 51–59.

Reference to a book:

Strunk Jr., W., White, E.B., 2000. The Elements of Style, fourth ed. Longman, New York.

Reference to a chapter in an edited book:

Mettam, G.R., Adams, L.B., 2009. How to prepare an electronic version of your article, in: Jones, B.S., Smith ,

R.Z. (Eds.), Introduction to the Electronic Age. E-Publishing Inc., New York, pp. 281–304.

Journal abbreviations source

Journal names should be abbreviated according to

Index Medicus journal abbreviations: http://www.nlm.nih.gov/tsd/serials/lji.html;

List of title word abbreviations: http://www.issn.org/2-22661-LTWA-online.php;

CAS (Chemical Abstracts Service): http://www.cas.org/sent.html.

Video data

Elsevier accepts video material and animation sequences to support and enhance your scientific research.

Authors who have video or animation files that they wish to submit with their article are strongly encouraged to

include these within the body of the article. This can be done in the same way as a figure or table by referring to

the video or animation content and noting in the body text where it should be placed. All submitted files should

be properly labeled so that they directly relate to the video file's content. In order to ensure that your video or

animation material is directly usable, please provide the files in one of our recommended file formats with a

preferred maximum size of 50 MB. Video and animation files supplied will be published online in the electronic

version of your article in Elsevier Web products, including ScienceDirect: http://www.sciencedirect.com. Please

supply 'stills' with your files: you can choose any frame from the video or animation or make a separate image.

These will be used instead of standard icons and will personalize the link to your video data. For more detailed

instructions please visit our video instruction pages at http://www.elsevier.com/artworkinstructions. Note: since

video and animation cannot be embedded in the print version of the journal, please provide text for both the

electronic and the print version for the portions of the article that refer to this content.

Supplementary data

Elsevier accepts electronic supplementary material to support and enhance your scientific research.

Supplementary files offer the author additional possibilities to publish supporting applications, high-resolution

images, background datasets, sound clips and more. Supplementary files supplied will be published online

alongside the electronic version of your article in Elsevier Web products, including ScienceDirect:

http://www.sciencedirect.com. In order to ensure that your submitted material is directly usable, please provide

the data in one of our recommended file formats. Authors should submit the material in electronic format

together with the article and supply a concise and descriptive caption for each file. For more detailed instructions

please visit our artwork instruction pages at http://www.elsevier.com/artworkinstructions.

Anexo 9

Normas de Publicação do periódico The Journal of the American Medical Association

(JAMA) para o artigo apresentado no Capítulo 5

All manuscripts must be submitted online via the JAMA online manuscript submission and

review system. At the time of submission, complete contact information (affiliation,

postal/mail address, email address, telephone and fax numbers) for the corresponding author

is required. First and last names, email addresses, and institutional affiliations of all coauthors

are also required. After the manuscript is submitted, the corresponding author will receive an

acknowledgment confirming receipt and a manuscript number. Authors will be able to track

the status of their manuscripts via the online system. After manuscript submission, all authors

of papers under consideration for publication will be sent a link to the Authorship Form to

complete and submit (see sample Authorship Form). See Manuscript Checklist, Manuscript

Preparation and Submission Requirements,1,2 and other details in these instructions for

additional requirements.

Cover Letter

Include a cover letter and complete contact information for the corresponding author

(affiliation, postal/mail address, email address, and telephone number) and whether the

authors have published or submitted any related papers from the same study (see

Duplicate/Previous Publication or Submission).

Manuscript Style

Manuscripts should be prepared in accordance with the AMA Manual of Style, 10th edition,1

and/or the ICMJE Recommendations for the Conduct, Reporting, Editing, and Publication of

Scholarly Work in Medical Journals.2

Manuscript Components

Include a title page, abstract, text, references, and as appropriate, figure legends, tables, and

figures. Start each of these sections on a new page, numbered consecutively, beginning with

the title page.

Recommended File Sizes

We recommend individual file sizes of no more than 500 kB and not exceeding 1 MB, with

the total size for all files not exceeding 5 MB (not including any video files).

Manuscript File Formats

For submission and review, please submit the manuscript as a Word document. Do not submit

your manuscript in PDF format.

Use 10-, 11-, or 12-point font size, double-space text, and leave right margins unjustified

(ragged).

Title Page

The title page should include a word count for text only (eg, not including abstract,

acknowledgment, or references) and the full names, highest academic degrees, and affiliations

of all authors. If an author’s affiliation has changed since the work was done, the new

affiliation also should be listed.

http://manuscripts.jama.com/

http://manuscripts.jama.com/

http://jama.jamanetwork.com/DocumentLibrary/InstructionsForAuthors/JAMA/auinst_crit.pdf

http://www.amamanualofstyle.com/

http://icmje.org/recommendations/

http://icmje.org/recommendations/

Title

Titles should be concise, specific, and informative and should contain the key points of the

work.1(p8) Please limit the length of titles to 150 characters for reports of research and other

major articles and 100 characters for Editorials, Viewpoints, Commentaries, and Letters. For

scientific manuscripts, overly general titles are not desirable and questions and declarative

sentences should be avoided. For reports of clinical trials, meta-analyses, and systematic

reviews, include the type of study as a subtitle (eg, A Randomized Clinical Trial, A Meta-

analysis, A Systematic Review). For reports of other types of research, do not include study

type or design in the title or subtitle.

Abstracts

Include a structured abstract of no more than 350 words for reports of original data, reviews,

and meta-analyses. Abstracts should be prepared in JAMA style—see instructions for

preparing abstracts below. For other major manuscripts, include an unstructured abstract of no

more than 200 words that summarizes the objective, main points, and conclusions of the

article. Abstracts are not required for Editorials, Viewpoints, and some special features.

All reports of original data, systematic reviews, and meta-analyses should be submitted with

structured abstracts as described below. No information should be reported in the abstract that

does not appear in the text of the manuscript.

Abstracts for Reports of Original Data:

Reports of original data should include an abstract of no more than 350 words using the

headings listed below. For brevity, parts of the abstract may be written as phrases rather than

complete sentences. Each section should include the following content:

Importance: The abstract should begin with a sentence or 2 explaining the clinical (or other)

importance of the study question.

Objective: State the precise objective or study question addressed in the report (eg, “To

determine whether…”). If more than 1 objective is addressed, the main objective should be

indicated and only key secondary objectives stated. If an a priori hypothesis was tested, it

should be stated.

Design: Describe the basic design of the study. State the years of the study and the duration of

follow-up. If applicable, include the name of the study (eg, the Framingham Heart Study). As

relevant, indicate whether observers were blinded to patient groupings, particularly for

subjective measurements.

Setting: Describe the study setting to assist readers to determine the applicability of the report

to other circumstances, for example, general community, a primary care or referral center,

private or institutional practice, or ambulatory or hospitalized care.

Participants: State the clinical disorders, important eligibility criteria, and key

sociodemographic features of patients. The numbers of participants and how they were

selected should be provided (see below), including the number of otherwise eligible

individuals who were approached but refused. If matching is used for comparison groups,

characteristics that are matched should be specified. In follow-up studies, the proportion of

participants who completed the study must be indicated. In intervention studies, the number

of patients withdrawn because of adverse effects should be given. For selection procedures,

these terms should be used, if appropriate: random sample (where random refers to a formal,

randomized selection in which all eligible individuals have a fixed and usually equal chance

of selection); population-based sample; referred sample; consecutive sample; volunteer

sample; convenience sample.

Note: the preceding 3 sections are usually combined for accepted papers during the editing

process as “Design, Setting, and Participants,” but for manuscript submission these sections

should be kept separate.

Intervention(s) for clinical trials or Exposure(s) for observational studies: The essential

features of any interventions, or exposures, should be described, including their method and

duration. The intervention, or exposure, should be named by its most common clinical name,

and nonproprietary drug names should be used.

Main Outcome(s) and Measure(s): Indicate the primary study outcome measurement(s) as

planned before data collection began. If the manuscript does not report the main planned

outcomes of a study, this fact should be stated and the reason indicated. State clearly if the

hypothesis being tested was formulated during or after data collection. Explain outcomes or

measurements unfamiliar to a general medical readership.

Results: The main outcomes of the study should be reported and quantified, including

baseline characteristics and final included/analyzed sample. Include absolute numbers and

measures of absolute risks (such as increase/decrease or absolute differences between groups),

along with confidence intervals (for example, 95%) or P values. Approaches such as number

needed to treat to achieve a unit of benefit may be included when appropriate. Measures of

relative risk also may be reported (eg, relative risk, hazard ratios) and should include

confidence intervals. Studies of screening and diagnostic tests should report sensitivity,

specificity, and likelihood ratio. If predictive value or accuracy is reported, prevalence or

pretest likelihood should be given as well. All randomized controlled trials should include the

results of intention-to-treat analysis, and all surveys should include response rates.

Conclusions and Relevance: Provide only conclusions of the study that are directly

supported by the results. Give equal emphasis to positive and negative findings of equal

scientific merit. Also, provide a statement of relevance indicating implications for clinical

practice or health policy, avoiding speculation and overgeneralization. The relevance

statement may also indicate whether additional study is required before the information

should be used in clinical settings.

Trial Registration: For clinical trials, the name of the trial registry, registration number, and

URL of the registry must be included.

Methods and Statistics

Describe statistical methods with enough detail to enable a knowledgeable reader with access

to the original data to reproduce the reported results. When possible, quantify findings and

present them with appropriate indicators of measurement error or uncertainty (such as

confidence intervals). Avoid relying solely on statistical hypothesis testing, such as the use of

P values, which fails to convey important quantitative information. Give details about

randomization. Describe the methods for and success of any blinding of observations. Report

complications of treatment. Give numbers of observations. Report losses to observation (such

as dropouts from a clinical trial). For multivariate models, report all variables included in

models, and report model diagnostics and proportion of variance explained by both individual

variables and the complete model.

Put a general description of methods in the “Methods” section. Restrict tables and figures to

those needed to explain the argument of the article and to assess its support. Use graphs as an

alternative to tables with many entries; do not duplicate data in graphs and tables. Avoid

nontechnical uses of technical terms in statistics, such as random (which implies a

randomizing device), normal, significant, correlations, and sample. Define statistical terms,

abbreviations, and most symbols. Provide a brief description of statistical tests used and levels

of significance to the Statistical Analysis paragraph in the Methods section.

Abbreviations

Do not use abbreviations in the title or abstract and limit their use in the text. Expand all

abbreviations at first mention in the text.

Units of Measure

Laboratory values are expressed using conventional units of measure, with relevant Système

International (SI) conversion factors expressed secondarily (in parentheses) only at first

mention. Articles that contain numerous conversion factors may list them together in a

paragraph at the end of the Methods section. In tables and figures, a conversion factor to SI

should be presented in the footnote or legend. The metric system is preferred for the

expression of length, area, mass, and volume. For more details, see the Units of Measure

conversion table on the website for the AMA Manual of Style.1

To read more about units of measure, click here.

Names of Drugs, Devices, and Other Products

Use nonproprietary names of drugs, devices, and other products, unless the specific trade

name of a drug is essential to the discussion.1(pp567-569)

Gene Names, Symbols, and Accession Numbers

Authors describing genes or related structures in a manuscript should include the names and

official symbols provided by the US National Center for Biotechnology Information (NCBI)

or the HUGO Gene Nomenclature Committee. Before submission of a research manuscript

reporting on large genomic data sets (eg, protein or DNA sequences), the data sets should be

deposited in a publicly available database, such as NCBI’s GenBank, and a complete

accession number (and version number if appropriate) must be provided in the Methods

section or Acknowledgment of the manuscript.

Reproduced Material

JAMA does not republish text, tables, figures, or other material from other publishers, except

under rare circumstances. Please delete any such material and replace with originals.

References

Authors are responsible for the accuracy and completeness of their references and for correct

text citation. Number references in the order they appear in the text; do not alphabetize. In

text, tables, and legends, identify references with superscript Arabic numerals. When listing

references, follow AMA style and abbreviate names of journals according to the journals list

in PubMed. List all authors and/or editors up to 6; if more than 6, list the first 3 followed by

“et al.” Note: Journal references should include the issue number in parentheses after the

volume number.

Examples of reference style:

1 Youngster I, Russell GH, Pindar C, Ziv-Baran T, Sauk J, Hohmann EL. Oral, capsulized,

frozen fecal microbiota transplantation for relapsing Clostridium difficile infection.

JAMA. 2014;312(17):1772-1778.

http://www.amamanualofstyle.com/oso/public/jama/si_conversion_table.html

http://www.amamanualofstyle.com/oso/public/jama/si_conversion_table.html

http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-chapter-18

http://www.ncbi.nlm.nih.gov/

http://www.genenames.org/

http://www.ncbi.nlm.nih.gov/Genbank

http://www.ncbi.nlm.nih.gov/sites/entrez?db=PubMed

2 Murray CJL. Maximizing antiretroviral therapy in developing countries: the dual challenge

of efficiency and quality [published online December 1, 2014]. JAMA.

doi:10.1001/jama.2014.16376.

3 Centers for Medicare & Medicaid Services. CMS proposals to implement certain disclosure

provisions of the Affordable Care Act.

http://www.cms.gov/apps/media/press/factsheet.asp?Counter=4221. Accessed January

30, 2012.

4 McPhee SJ, Winker MA, Rabow MW, Pantilat SZ, Markowitz AJ, eds. Care at the Close of

Life: Evidence and Experience. New York, NY: McGraw Hill Medical; 2011.

For more examples of electronic references, click here.

http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div1-46

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