Bledsoe v1 ch05_lecture

Copyright © 2017, 2013, 2009 Pearson Education, Inc. All Rights Reserved.

Bryan E. BledsoeRichard A. Cherry Robert S. Porter

Paramedic Care: Principles & PracticeVolume 1, 5e

Chapter 5EMS Research



Standard• Preparatory (Research)



Competency• Integrates comprehensive knowledge of EMS

systems, the safety and well-being of the paramedic, and medical–legal and ethical issues, which is intended to improve the health of EMS personnel, patients, and the community.



Introduction• Solid and objective research program will drive

EMS practices in the coming years.

• Outcomes-based research: determine whether procedure, drug, treatment, strategy improves patient outcomes (mortality, morbidity, quality of life).



Introduction• National EMS Research Agenda (2001)

– Develop EMS researchers; support them early in their careers

– Collaboration between EMS researchers and other disciplines

– Establish funding stream for EMS research within government



Introduction• National EMS Research Agenda (2001)

– Establish alternate funding source for EMS research outside of government

– Recognize need for EMS research– View research as necessary for improvement of patient

care– Enhance ethical approaches to research



Introduction• Research

– Key to maintaining focus on improving health of community in competitive and cost-conscious health care market.

– Ensures best possible patient care provided in prehospital and out-of-hospital settings.



Research and the Scientific Method• Science: state or fact of knowledge derived

through scientific method.

• Research: use of scientific method to study given issue.

• Scientific method: process by which scientists construct accurate representation of world; reliable, consistent, nonarbitrary.



Research and the Scientific Method• Steps of Scientific Method

– Observe and ask questions.– Collect, analyze, synthesize data.– Construct hypothesis.– Test hypothesis by experimentation.– Analyze results and draw conclusions.– Revise hypothesis.– Report results.



Figure 5-1 Steps of the scientific method.



Types of Research• Quantitative research: describes phenomena in

numbers.

• Qualitative research: describes phenomena in words.

• Mixed research: combination of quantitative and qualitative research; uses both numbers and words to describe phenomena being studied.



Table 5-1 Summary of Research Types

Quantitative Research Mixed Research Qualitative

Research

Scientific method

Researcher tests the hypothesis with data (deductive approach)

The researcher generates a hypothesis after

collecting data (inductive approach)

Deductive and inductive

Focus Narrow topic Variable topic Wide topic

Behavior Studied under controlled conditions

Studied in more than one context

Studied in natural environment

Nature of reality Objective Commonsense

(pragmatic) Subjective

Nature of data Numbers Numbers and words WordsData analysis Statistical Statistical and words Words

Results Generalizable May be generalizable NongeneralizableReport Statistical Mixed Narrative



Types of Research• Most medical research is quantitative.

• Retrospective research: examines information that already exists.

• Prospective research: study starts now; examines what happens from this point forward.



Types of Research• Quantitative versus Qualitative Research

– Quantitative research is objective and specific. Determines relationship between one thing (independent

variable) and another (dependent or outcome variable) and describes it with numbers (statistics).




– Quantitative research is objective and specific. Independent variable: affects dependent variable under study. Dependent variable (outcome): variable being affected.




– Nonexperimental quantitative research: independent variables that cannot be manipulated for one reason or another.

– Survey-quantitative research: reflects public opinion for marketing and social science research.




– Qualitative research relies on collection of qualitative (nonnumeric) data. Seeks "why" and not "how" of phenomena being studied Occurs in natural setting Role in quality assurance



Types of Research• Prospective versus Retrospective Studies

– Retrospective studies: look at existing data.– Prospective studies: use research form or instrument

specifically designed for study; objective, accurate, complete.



Experimental Design• Experimental study: both control group (group of

subjects who do not have manipulation of independent variable) and treatment (experimental) group.

– Subjects randomly assigned to one group– Ensure demographics between groups similar



Experimental Design• Quasiexperimental study: scientist does not

randomly assign subjects to the study groups.– Greater chance of having groups demographically

different, and of introduction of bias– Considered less valid than experimental studies



Experimental Design• Observational study: does not have control group.

– Single or multiple groups studied without comparison to control

– Scientist does not control variables.– Less valid than experimental or quasiexperimental

studies – Important role in medicine



Experimental Design• Specific Study Types

– Meta-analysis of randomized controlled trials: combined results of several prior studies.

– Randomized controlled trials (RCTs): subjects randomized into treatment group and control group. Single or double blind study



Figure 5-2 Hierarchy of validity of study types. The most valid type of study is at the top of the pyramid, the least valid at the bottom.



Figure 5-3 Meta-analysis is an analysis of the combined results of several prior studies.




– Nonrandomized controlled trials: control group and treatment group; assignment to groups not randomized.

– Also called quasiexperimental studies– Less validity than RCT, but utility in some

circumstances




– Cohort study: observational; subjects who have certain condition and/or who receive particular treatment followed over time; compared with another group not affected by condition.



Figure 5-7 A cohort is a group of subjects who share a certain characteristic. For example, all may be cancer patients. A cohort study observes and compares the cohort group with a group whose members do not have the cohort characteristic.




– Cross-sectional study (analysis): observational; various groups compared without control; looks at single point in time.

– Case series: looks at group of patients with similar condition.




– Case report: structured study of single patient who is unique or interesting to medical community in general.

– Expert opinions, editorials, rational conjecture: suitable for use before scientific research is available or while scientific research is occurring.




– Animal research (in vivo): understanding how certain drugs and procedures affect biological systems. Findings in one species do not necessarily apply to other

species. Computer modeling starting to replace aspects of animal

research.




– Bench research (in vitro): scientific research at most basic level; important in learning how universe functions.

– Quality of research supporting clinical practice: stratify scientific evidence based on type and validity of experimental designs used.



Experimental Design• Study Validity

– Validity: whether or how well study supports the conclusions

– External validity : assures results can be generalized, or possess generalizability

– Internal validity: ensures results can be attributed to the cause



Ethical Considerationsin Human Research• While medical research essential, overriding

concern is rights of those who serve as subjects in studies.

• Nuremburg Code of 1947: first code to guide ethical practice in human research.

• Tuskegee University experiments



Ethical Considerations in Human Research• Helsinki Declaration: subject makes informed

decision about participating in research; assurance by researcher that patient's safety protected.

• Ethical Principles and Guidelines for the Protection of Human Subjects of Research



Ethical Considerations in Human Research• Institutional Review Board (IRB)

– Committee that approves, monitors, reviews human research

– Goal is to protect human subjects.– Approves/disapproves study before it begins.– Requires researchers to modify or terminate study if

subjects at risk.



An Overview of Statistics• Statistics: mathematics of collecting and analyzing

data to draw conclusions and make predictions.– Descriptive statistics: describe basic features of data

obtained in a study.– Inferential statistics: information from sampled

observations of population; make conclusions about population.



An Overview of Statistics• Descriptive Statistics

– Describe nature of sample.– Mean (average): add values, then divide sum by

number of values involved.– Median: put the values into numerical order, then find

middle value.



An Overview of Statistics• Descriptive Statistics

– Mean and median: measures of central tendency; indicate center of group.

– Variance: take each value, then subtract mean from it.– Standard deviation (SD or σ): take square root of

variance.– Mode: most common value in set of data.



An Overview of Statistics• Inferential Statistics

– Estimating parameters of population.– Sampling error: estimation of difference between value

obtained from sample and value that would be obtained from entire population.

– Confidence interval: variability added or subtracted to original proportion.



An Overview of Statistics• Quantitative and Qualitative Statistics

– Qualitative statistics: data nonnumeric in nature; assigned number indicating ranking or ordering of importance or severity. Nominal or ordinal data

– Quantitative statistics: numerical in nature.



An Overview of Statistics• Other Types of Data

– T test– Analysis of variance (ANOVA)– Chi square test– Odds ratio: how strong association is between risk

factor and condition it is associated with.



Format of a Research Paper• Abstract: need for study, research methods used,

results encountered.

• Introduction: description of pertinent, previously published papers on subject of investigation.

– Why undertaken; purpose of study; what hypothesis authors wanted to test



Table 5-2 Research Paper Format for Some Emergency Medicine Journals

Prehospital Emergency Care

Annals of Emergency Medicine

Academic Emergency Medicine

AbstractIntroductionMethodsResultsDiscussionConclusionsReferences

AbstractIntroductionMethodsResultsLimitationsDiscussionReferences

AbstractIntroductionMethodsResultsDiscussionLimitationsConclusionsReferences



Format of a Research Paper• Methods section: how authors conducted study.

• Results: researchers provide data (summary).

• Discussion section: authors interpret findings; describe significance.

• Summary (conclusion): brief recap of main findings of study.



How a Research Paper Is Published• Submit to scientific journal for publication.

• All peer-reviewed journals follow same general procedure.

• After receiving paper, editor sends to one or more members of review board.

• Reviewers blinded as to names of authors and affiliated institutions.



How a Research Paper Is Published• Reviewers read paper; evaluate for adherence to

standards of research methods, pertinence to field, value for practitioners.

• Reviewers send comments to editor, who then decides whether to publish it, send it back for revisions, or reject it.



Accessing the Scientific Literature• Journal publishers have archived their

publications online. – Can be downloaded as portable document files (PDFs)

or directly.– Most journals require subscription or library affiliation to

access.– Some are free (open-access journals).



Accessing the Scientific Literature• National Libraries of Medicine: accessible

database of medical and scientific literature (PubMed).

• Loansome Doc: document retrieval service accessed through web.



What to Look for When Reviewing a Study• Was research peer reviewed?

• Was there a clear hypothesis or study purpose?

• Was study approved by IRB, and was it conducted ethically?

• Was study type appropriate?



What to Look for When Reviewing a Study• What population were the researchers studying?

• What inclusion and exclusion criteria did researchers use?

• How did investigators draw their sample?

• How many groups were patients divided into; were patients assigned to control and study groups properly?



What to Look for When Reviewing a Study• Were control and study groups the proper size?

• Were effects of confounding variables (other things that may have affected study outcome) taken into account?

• What kind of data did investigators collect; did they analyze data with proper statistical tests?



What to Look for WhenReviewing a Study• Were results reported properly?

• How likely is it that the study results would occur by chance alone?

• Are author's conclusions logical and based on the data?

• How good was EMS system in which study was done?



Applying Study Results to Your Practice• Evaluate the field and its knowledge base to make

informed decision about how to interpret a piece of research.

• Distinguish between statistical and clinical significance of the study.



Applying Study Results to Your Practice• Be sure patient similar enough to study group to

benefit from intervention.

• Speak to management of your organization, especially medical director.



Participating in Research• Determine the question.

• Prepare hypotheses (null/research).

• Decide what you wish to measure and how you will do it.

• Define population.

• Identify limitations of your study.



Participating in Research• Get approval of proper authorities (IRB/principal

investigator [PI]).

• Determine how you will get informed consent from study subjects.

• Gather and analyze data.

• Determine what you will do with results.



Evidence-Based Decision Making• Use of best practices and clinical pathways based

on clinical and scientific evidence ensures care is safe, efficacious, cost-effective.

• Formulate question about appropriate treatments.

• Medical literature searched and organized.



Evidence-Based Decision Making• Scientific evidence stratified based on validity and

reliability.

• If evidence supports change in practice, change is made.

• Once practice changed, ongoing evaluation must be carried out.



Table 5-5 Applying Classification of Recommendations and Level of Evidence (1 of 4)

Size of Treatment EffectClass I Class IIa Class IIb Class III

Estimate of Certainty (Precision) of Treatment Effect

Benefit >>> Risk

Procedure/ TreatmentSHOULD be performed/Administered

Benefit >> RiskAdditional studies with focused objectives needed

IT IS REASONABLE to perform procedure/ administer treatment

Benefit ≥ RiskAdditional studies withbroad objectives needed; Additional registry data would be helpful

IT IS NOTUNREASONABLE to perform procedure/administer treatment

Risk ≥ BenefitNo additional studies needed

Procedure/ Treatment should NOT be performed/administered SINCE IT IS NOT HELPFUL AND MAY BE HARMFUL



Table 5-5 (continued) Applying Classification of Recommendations and Level of Evidence (2 of 4)

Size of Treatment Effect

Class I Class IIa Class IIb Class III


Level A

Multiple (3–5) population risk strata evaluated

General consistency of direction and magnitude of effect

• Recommendation that procedure or treatment is useful/effective

• Sufficient evidence from multiple randomized trials or meta-analyses

• Recommendation in favor of treatment or procedure being useful/effective

• Some conflicting evidence from multiple randomized trials or meta-analyses

• Recommendation's usefulness/ efficacy less well established

• Greater conflicting evidence from multiple randomized trials or meta-analyses

• Recommend-ation that procedure or treatment not useful/effective and may be harmful

• Sufficient evidence from multiple randomized trials or meta-analyses







Level B

Limited (2–3)population risk strataevaluated

• Recommend-ation that procedure or treatment is useful/effective

• Limited evidence from single randomized trial or non-randomized studies

• Recommend-ation in favor of treatment or procedure being useful/effective

• Some conflicting evidence from single randomized trial or nonrandomized studies

• Recommendation's usefulness/efficacy less well established

• Greater conflicting evidence from single randomized trial or nonrandomized studies

• Recommendation that procedure or treatment not useful/effective and may be harmful

• Limited evidence from single randomized trial or non-randomized studies







Level C

Very limited (1–2)population risk strataevaluated

• Recommendation that procedure or treatment is useful/effective

• Only expert opinion, case studies, or standard of care

• Recommendation in favor of treatment or procedure being useful/effective

• Only diverging expert opinion, case studies, or standard of care

• Recommendation's usefulness/efficacy less well established

• Only diverging expert opinion, case studies, or standard of care

• Recommendation that procedure or treatment not useful/effective and may be harmful

• Only expert opinion, case studies, or standard of care



Summary• Solid, well-conducted scientific research is key to

improving prehospital care.

• It is essential to prove paramedics make a difference in terms of reducing mortality, morbidity, pain, and suffering.

• Benefit: increased revenue stream.

• Future of EMS depends on aggressive research program.