PHARM 3823
Health & Biostats
Evidence-Based Medicine
or Please Pass the PICO…
Frederic Murray
Assistant Professor
MLIS, University of British Columbia
BA, Political Science, University of Iowa
Instructional Services Librarian
Al Harris Library
frederic.murray@swosu.edu
Peer Reviewed
Evidence Based Medicine
• Evidence-based medicine (EBM) is
using and carrying out practices based
on the best available knowledge.
EBM
Clinical Expertise
Best Research
Patient Preferences
Why Evidence Based Medicine?
• Exponential Growth in Medical
Literature
• Impossible for Medical Practitioners to
keep up
Why Evidence Based Medicine?
• There are 7827 articles relevant to
family practice published every month
• That’s 17 articles a day (every day) to
keep up…20 hours a day reading.
Why Evidence Based Medicine?
• There are a lot of Evidence Based
Review Sources that Synthesize and
critically appraise healthcare literature
• They can be found in Your Library
• Also….you’ll be needing this again in
Pharm 4302 Drug Information
Yale University
School of Medicine
Filtered Information Appraises the quality of studies and often make recommendations for practice
Unfiltered Evidence is not always available via filtered resources. Searching the primary literature may be
required
Evidence-Based Medicine
Five fundamental steps
• Step 1: Formulating a well-built question
• Step 2: Identifying articles and other evidence-based
resources that answer the question
• Step 3: Critically appraising the evidence to assess
its validity
• Step 4: Applying the evidence
• Step 5: Re-evaluating the application of evidence
and areas for improvement
The fundamental skill necessary to
conduct evidence-based medicine is
learning to design a Well-Built
Clinical Question.
Step 1: Well Built Question
• With clinical cases, there is often a
barrage of details to digest.
• To effectively search EBM resources,
you need to decide what details are
important.
Step 1: Well Built Question
•
•
•
•
what
what
what
what
about
about
about
about
the
the
the
the
Population?
Intervention?
Comparison?
Outcome?
PICO
P The patient’s disorder or disease
I The intervention or finding under review
C A comparison intervention (if applicable)
O The outcome
Pico: Example
• “In a 55-year-old man with a 35-yearold history of chronic smoking, would
the administration of bupropion as
compared to a nicotine replacement
therapy (NRT) be a better therapy in
causing long-term abstinence from
smoking?
PICO Example
•
“In a 55-year-old man with a
35-year-old history of chronic
smoking, would the
administration of bupropion as
compared to a nicotine
replacement therapy (NRT) be
a better therapy in causing
long-term abstinence from
smoking?
PICO Example
PICO: A State of Mind
• A systematic way to identify important
concepts in a case
• Formulate a question for searching
• Often you will often not have a
comparison intervention
Framing Good Questions
• Describe the subject
– How would I describe a group of patients similar
to this one?”
• Define which intervention
– x-ray versus an MRI
• Define the type of outcome
– changes in a physical sign
– outcome of a diagnostic test
– response to therapy
I Class Exercise: Worksheet 1a#
• A nine-year-old girl presents in the ER with diffuse
abdominal pain and loss of appetite. You suspect
appendicitis, and need to decide which imaging
modality is best for making the diagnosis—CT or
ultrasound.
I Class Exercise: Worksheet 1a#
P
I
C
O
Child with suspected appendicitis
CT
Ultrasound
Reliable diagnosis of appendicitis
Is ultrasound or CT better for diagnosing
appendicitis in a child?
Step 2: Database/Resource Searching
These resources generally fall into three categories
• General information (background)
resources
• Filtered resources
• Unfiltered resources.
Build a Broader Lexicon: (MeSH)
Worksheet 1b#
• Use MeSH to discover new terms
• Search MeSH to find new entry terms
for ultrasound…
(in class we’re only concerned with the C in
PICO…[for now])
MeSH is the National Library of Medicine's controlled
vocabulary thesaurus
General Resources
• Stedman's Online Medical Dictionary
– Database
• Current Diagnosis and Treatment
– Ebrary
• Drug information handbook –Lexi-Comp
– 2nd floor Library
Filtered Resources
• Used to decide on a course of action for a patient
(diagnosis, treatment, etc.)
• Clinical experts pose a question and then synthesize
"evidence" to state conclusions based on the
available research.
• The literature has been searched and results
evaluated to provide an answer to a clinical question
Filtered Resources
• Annual Reviews Online
• Cochrane Database of Systematic
Reviews (CDSR)
• National Guideline Clearinghouse
National Guideline Clearinghouse
• Hypertension
– Age of Target Population
– Guideline Category
– Intended Users
Unfiltered Resources
• Search the unfiltered resources to see if any
new research has been done
• Unfiltered resources provide the most recent
information…but
• Not designed for answering clinical questions
• Evaluation takes time, effort and expertise
Unfiltered Resources
• Medline
• Medline PubMed
• CINAHL
• OVID
Search Example
II. Class Exercise:
Search Otitis Media
• Cochrane Database of Systematic Reviews
(CDSR) Filtered
• MedLine Plus Unfiltered
• Stedman's Online Medical Dictionary
General
Step 3: Critical Appraisal
• If the study is from a primary source (one that
provides original data on a topic with no commentary)
• Do a “validity” (closeness-to-truth) check
Dachs, R., Darby-Stewart, A., & Graber, M. (2012).
Antibiotics for acute otitis media in young children: the case
of the shifting end points. American Family Physician, 85(2),
104.
Step 3: Critical Appraisal
•
•
•
•
Diagnosis
Therapy
Harm
Prognosis
Step 3: Critical Appraisal
Therapy
Diagnosis
• Was the assignment of
• Did patient sample
patients to treatment
include appropriate
groups randomized?
spectrum of patients to
those found in general • Were all enrolled patients
practice?
accounted for at the
conclusion of the study?
• Was the gold standard
applied to all cases?
• Were the treatment
groups similar at the start
of the study?
Step 3: Critical Appraisal
Harm
• Were exposures and
outcomes measured
similarly?
• Was the follow-up
adequate?
Prognosis
• Was the patient sample
representative?
• Was the length of the
follow-up adequate?
• Was the follow-up
complete?
III. Class Exercise: Therapy Questions
Dachs, R., Darby-Stewart, A., & Graber, M. (2012).
Antibiotics for acute otitis media in young children: the
case of the shifting end points. American Family
Physician, 85(2),
104.
• Was the assignment of patients to treatment groups
randomized?
• Were all enrolled patients accounted for at the
conclusion of the study?
• Were the treatment groups similar at the start of
the study?
Step 4: Applying the Evidence
• Decide how the study and/or other
information applies to your question
– Diagnosis
– Therapy
– Harm
– Prognosis
Step 4: Applying the Evidence
Therapy
Diagnosis
• According to the study
• Is the test available,
results how much would
accurate and affordable?
my patient benefit from
• Can I estimate the
the treatment?
pretest probability of the
disease in question?
Step 4: Applying the Evidence
Harm
• Can the study results be
applied to my patient?
• Are there alternative
therapies?
• What is my patient’s risk
for adverse effects?
Prognosis
• How will the evidence
influence my choice of
treatment?
Step 5: Re-evaluating the Evidence
• Was the diagnosis and treatment
successful?
• Is there new information/data in the
literature?
• How can I improve and/or update my
clinical decisions?
HOW TO MANAGE ALL THIS INFORMATION?
IV. Class Exercise
Worksheet 1c#
– Research the PICO Question:
Is ultrasound or CT better for diagnosing
appendicitis in a child?
– Select two filtered & one unfiltered
database
– Record your findings ( hint: use the
abstracts)
V. Class Exercise
Worksheet 2#
– Develop PICO Questions for the case
studies
– Search Filtered/Unfiltered database to
answer your question (1 source)
– List Citation (APA)
Questions?
• Contact me:
• Frederic Murray
• 774-7113
• frederic.murray@swosu.edu
Thanks!