Copyright © 2020 pubrica. All rights reserved 1

What is a Systematic Review

Dr. Nancy Agens, Head,

Technical Operations, Pubrica

sales@pubrica.com

In Brief

A systematic review is a secondary

research as it requires a careful analysis

of the quality, quantity, and consistency

of research findings. Systematic reviews

formulate research questions that are

specifically targeted and designed to

provide a complete summary of the issue

based on evidence. The methodology used

in systematic reviews is specific and

precise, which intends to minimize bias by

increasing the reliability of the drawn

conclusion.

I. INTRODUCTION

A systematic review is a process of

identifying comprehensive studies for a

research specific question through

evaluating the methods of the study,

summarizing the results, presenting key

findings, identifying reasons for produced

results across the study and mentioning

limitations with current knowledge. A

systematic review is the most reliable

source of evidence for clinical practices as

it delivers thorough summary of primary

research in response to the defined

research question and it is also known as

secondary research because of the nature

and use of existing research study. Though

systematic review can be performed on all

primary research, they are often used for

guideline development, and the findings

are applied mainly within the healthcare

systems. In a systematic review, the

compiled information tends to be explicit

and more transparent using reproducible

methods. Further, it expresses a precise

aim through rigorous search with

predetermined eligibility criteria for

studies, an assessment of the validity of

the findings, a systematic presentation and

synthesis of the included primary research

studies. The methodology used in

systematic reviews is specific and precise,

which intends to minimize bias by

increasing the reliability of the drawn

conclusion. The produced results of a

systematic review can be summarized

either in text or graphic form, and it

depends upon the nature of the primary

data.

As like primary research studies, there are

reporting standards designed for

systematic reviews as well. The PRISMA

(Preferred Reporting Items for Systematic

reviews and Meta-Analyses), provides a

set of regulations on how to report a

systematic review. Likewise, for selecting

a secondary research question, there are

designated formats. A systematic review

question typically focused research

question with narrow parameters and

usually fitted into the PICO question

format. One such example is "In people

with multiple sclerosis, what is the extent

to which a walking intervention, compared

to no intervention, improves self-report

fatigue?". Based on the specific guidelines,

the primary two organization which

administer the conducting of a systematic

review are the Campbell Collaboration and

the Cochrane Collaboration. While the

Cochrane Collaboration focuses on the

health sciences subject area, the Campbell

collaboration works on other areas such as

crime and justice, international

development, education and social welfare.

In addition to these organizations, the

individual research team can work on

systematic review in attempting to answer

a research question.

Copyright © 2020 pubrica. All rights reserved 2

II. WHAT MAKES AN EXCELLENT

SYSTEMATIC REVIEW?

A good systematic review will include,

A focused question

Inclusion/exclusion criteria

Search strategy

Study selection

Assess the quality of studies

Synthesize study results

Analysis and limitations

A focused question - a systematic review

is a research method used to address a

specific research question and formulating

a well-constructed research question is

essential for a successful review.

Inclusion/exclusion criteria – It studies

the writers included or excluded and the

reason. For instance, the most reliable

method for conducting a review through

randomized studies whereas for including

or excluding studies, the author needs a

logical reason.

Search strategy – The reviewer must

explain the methods used for finding

relevant studies which include published

and unpublished clinical trial reports,

online database search, as well as

approaching experts in finding

unpublished data.

Study selection – Need to identify suitable

study criteria and collect relevant data for

conducting a systematic review.

Assess the quality of studies – It helps in

identifying the risk of bias in secondary

research

Synthesize study results - Upon similarity

on the included data, the author must

determine the effectiveness of an

intervention using meta-analysis. Whereas

the study is not much similar, the author

can provide a narrative analysis by

describing the initial results.

Analysis and limitations – The review

should discuss the addressed area of study,

the findings, and how the review results

change the existing limitations.

Different types of reviews:

There are many types of reviews

addressing questions of effectiveness,

questions about the prevalence of

diagnostic accuracy, and prognosis.

Different types of reviews include,

Literature Review

Meta-analysis

Rapid review

Scoping review

Systematic review

Systematized review

Umbrella review

III. DIFFERENCES BETWEEN SYSTEMATIC AND LITERATURE REVIEWS

Key section Systematic review Literature review

Question Mainly focused on one

question

It describes an overview and

not based on a single

question

Protocol It follows peer review

protocol or plan

It has no protocol

Background Both the review presents the summaries of the available

literature on a topic

Objectives Study-specific objectives are

identified

No such objectives will be

identified

Inclusion and exclusion

criteria

There are specific criteria to

be stated before the review

is conducted

Not mandatorily specified

Search strategy A systematic search will be The search strategy will not

Copyright © 2020 pubrica. All rights reserved 3

conducted

be mentioned

Process of selecting articles Clear and explicit Not described

Process of evaluating

articles

A comprehensive evaluation

of the study as it mainly

used in formulating

guidelines

Evaluation of study quality

may not be included

Process of extracting

relevant information

Research question specific

information extraction

Extracting relevant

information is not specific to

a single question

Results and data synthesis Clear summaries of studies

will be provided based on

evidence

Overview based on reviews

where the quality of articles

may not be specified.

Discussion An expert or group of professionals write them with a well-

grounded knowledge of the issues.

Reproduced from: Learning how to undertake a systematic review: part 1 DOI:

10.7748/ns2010.08.24.50.47.c7939

In summary, a systematic review is a

search of all sources of evidence for

relevant studies or on research question

specific study. Predetermined reproducible

criteria to screen for eligibility and

relevance assessment of titles and the

abstracts will be followed. Each study will

then be assessed in terms of

methodological quality, and finally, the

evidence is synthesized.

REFERENCE

1. Bettany-Saltikov, J & Fernandes, T 2010, 'Learning

how to undertake a systematic review: Part

1', Nursing Standard (through 2013), vol. 24, no.

50, pp. 47-55

2. https://www.spi.ox.ac.uk/what-makes-a-good-

systematic-review

3. The Systematic Review: An Overview American

Journal of Nursing: March 2014 - Volume 114 -

Issue 3 - p 53-58. DOI:

10.1097/01.NAJ.0000444496.24228.2c

4. WilsonV. (2013). Research Methods: Systematic

Reviews. Evidence-Based Library and Information

Practice, 8(3), 83-84.

https://doi.org/10.18438/B8CP5Z

5. What is a systematic review? Jane Clarke Evid

Based Nurs 2011 14: 64

http://dx.doi.org/10.1136/ebn.2011.0049

6. https://libraryguides.mcgill.ca/knowledge-

syntheses/question