Bledsoe v1 ch05_lecture

Copyright © 2017, 2013, 2009 Pearson
Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Paramedic Care: Principles & Practice
Volume 1, 5e
Chapter 5
EMS Research

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Standard
• Preparatory (Research)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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).

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 5-1 Steps of the scientific method.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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 Words
Data analysis Statistical Statistical and words Words
Results Generalizable May be generalizable Nongeneralizable
Report Statistical Mixed Narrative

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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).

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Types of Research
– Quantitative research is objective and specific.
 Independent variable: affects dependent variable under study.
 Dependent variable (outcome): variable being affected.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Types of Research
– 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Types of 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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 5-3 Meta-analysis is an analysis of the combined results of several prior studies.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Experimental Design
– 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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Experimental Design
– 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Experimental Design
– 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Experimental Design
– 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Experimental Design
– 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Experimental Design
– 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Ethical Considerations
in 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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• 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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 5-2 Research Paper Format for Some Emergency Medicine Journals
Prehospital
Emergency Care
Annals of
Emergency Medicine
Academic
Emergency Medicine
Abstract
Introduction
Methods
Results
Discussion
Conclusions
References
Abstract
Introduction
Methods
Results
Limitations
Discussion
References
Abstract
Introduction
Methods
Results
Discussion
Limitations
Conclusions
References

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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).

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Accessing the Scientific Literature
• National Libraries of Medicine: accessible
database of medical and scientific literature
(PubMed).
• Loansome Doc: document retrieval service
accessed through web.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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?

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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?

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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?

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Reviewing 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?

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 5-5 Applying Classification of Recommendations and Level of Evidence (1 of 4)
Size of Treatment Effect
Class I Class IIa Class IIb Class III
EstimateofCertainty(Precision)of
TreatmentEffect
Benefit >>> Risk
Procedure/
Treatment
SHOULD be
performed/
Administered
Benefit >> Risk
Additional studies
with focused
objectives
needed
IT IS
REASONABLE
to perform
procedure/
administer
treatment
Benefit ≥ Risk
Additional studies
with
broad objectives
needed;
Additional registry
data would be
helpful
IT IS NOT
UNREASONABL
E to perform
procedure/
administer
treatment
Risk ≥ Benefit
No additional
studies needed
Procedure/
Treatment
should NOT be
performed/admi
nistered SINCE
IT IS NOT
HELPFUL AND
MAY BE
HARMFUL

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 5-5 (continued) Applying Classification of Recommendations and Level of Evidence
(2 of 4)
TreatmentEffect
Level A
Multiple (3–5)
population risk
strata
evaluated
General
consistency of
direction and
magnitude of
effect
• Recommendati
on that
procedure or
treatment is
useful/effective
• Sufficient
evidence from
multiple
randomized
trials or meta-
analyses
• Recommendati
on 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

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
(3 of 4)
TreatmentEffect
Level B
Limited (2–3)
population
risk strata
evaluated
• 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
• Recommendati
on that
procedure or
treatment not
useful/effective
and may be
harmful
• Limited
evidence from
single
randomized trial
or non-
randomized
studies

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
(4 of 4)
TreatmentEffect
Level C
Very limited
(1–2)
population
risk strata
evaluated
• Recommendati
on that
procedure or
treatment is
useful/effective
• Only expert
opinion, case
studies, or
standard of
care
• Recommendati
on in favor of
treatment or
procedure being
useful/effective
• Only diverging
expert opinion,
case studies, or
standard of care
• Recommendatio
n's
usefulness/effica
cy less well
established
• Only diverging
expert opinion,
case studies, or
standard of care
• Recommendati
on that
procedure or
treatment not
useful/effective
and may be
harmful
• Only expert
opinion, case
studies, or
standard of care

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
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.

Bledsoe v1 ch05_lecture

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