Transcript KSOM Y2 Evidence-based Medicine -

KSOM Y2
Evidence-Based Medicine:
Background & Resources
Emily Brennan, MLIS
Eileen Eandi, MLS
Joe Pozdol, MLIS
Evans Whitaker, MD, MLIS
[email protected]
[email protected]
[email protected]
[email protected]
Norris Medical Library, Rm. 102
2003 Zonal Ave.
Los Angeles, CA 90089-9130
Introduction
• We are…
• Personal Librarians for KSOM Y2:
– Last Name:
Ahn-Fecht
Fernandez-Lee
Leong-Penman
Perrin-Yasmeh
Pamela Corley
Eileen Eandi
Emily Brennan
(replacing Adrian Follette)
Evans Whitaker
• Ask questions!
• Please fill out evaluation forms at the end of class…
Context and Outline
• Class today -- an extension of Dr. Samet’s lecture of August 7, 2009
• Assignment given today and posted on library student portal
– Due date: August 28, 2009 to Curriculum Office
• Objectives of today’s session
I. EBM Background
A. Briefly review study types pertinent to EBM
B. Introduce evidence pyramid
C. Introduce levels of evidence
D. Introduce PICO and searchable clinical questions
II. EBM Resources
A. Introduce major sources of evidence-based information at USC
B. Provide search tips to promote maximally efficient searching
EBM BACKGROUND
EBM Defined
• Simple concept
– Use the best available evidence to make clinical
decisions…
• EBM process…
– Begins and ends with the patient
– Weighs 3 factors to make clinical decisions
• Best available clinical research
• Experience of individual clinician
• Patient preferences/characteristics
One Aspect of EBM
• “EBM encourages a healthy skepticism of every
practice in medicine and promotes a culture of
inquiry.”
– Sloane, P.D., Slatt, L.M., Ebell, M.H., Jacques, L.B., Smith,
M.A. (2008). Essentials of family medicine (5th ed.).
Philadelphia: Wolters, pp. 40.
Three Interacting Realms of EBM
Best available clinical evidence
The point at which
effecting Doctor-Patient
communication and
planning is informed by
the best evidence
Patient needs,
desires, resources
Clinician experience
Patient-Doctor Dyad – Not really changed through time
Stages of EBM Process
1.
Formulate search (based on patient interaction)
2.
Perform search
3.
Assess search results
• Relevance (does it apply to my patient?)
• Validity (are the findings of the articles true?)
4.
Apply results to your patient
5.
Reassess your patient  Repeat process as needed
You will see variations in the above depending on the author and the
field in which they work
Study Types
• Study types of most relevance to EBM
– Randomized Control Trial (primary literature)
• Participants are assigned randomly to treatment and
control groups
• Groups are compared over time
– Systematic Review (secondary literature)
• Reproducible methods used to locate and select articles
• Inclusion/exclusion criteria
– Meta analysis (secondary literature)
• Numerical data from separate studies combined using
statistical/mathematical methods
Evidence Pyramid
Source: http://library.downstate.edu/EBM2/2100.htm
Levels of Evidence (LOE)
• Another way to look at same idea…
• Confusing as…
– There are several systems
– None are universal
– All use a-d OR 1-5 OR some combination (e.g., 1a)
• Essential Evidence Plus collects some of these LOE systems
Levels of Evidence (LOE)
• Common finding in all LOE systems…
– Randomized controlled trial (RCT), Systematic review,
Meta analysis are considered “best evidence”
• Reduce the chance of author bias…
• However…
– Many questions have little or no evidence…
• Use the best evidence that exists
• May mean case reports!
A Heart Failure Scenario
•
65 yo male with history of hospitalization for congestive heart failure one year ago
beginning care with you today.
•
Medications: diuretic , angiotensin converting enzyme (ACE) inhibitor, and a statin.
•
Physical exam: BP of 124/78 in the right arm, sitting. His pulse is 85 and regular. His
weight is 80 kg which he states is his normal weight. He has clear lung fields and no
pretibial edema.
•
You order lab work, a chest x ray, a resting oximetry, and an echocardiogram.
– His lab work is all within normal limits.
– His CXR show clear lung fields, borderline cardiomegaly, and flattened diaphragms.
– His room air, resting oximetry is 95%.
– His echocardiogram shows a mildly dilated left ventricle, an ejection fraction of
30%, and evidence of his previous myocardial injury.
• Your question: Should I start this patient with chronic CHF on beta blockers,
specifically carvedilol?
Developing a Searchable
Question
• Clinical question:
– “For a 65 yo man with congestive heart failure and systolic
dysfunction, should carvedilol be prescribed?
– You might consider several outcomes (e.g., improved QOL,
decreased hospitalization, decreased mortality)
• Searchable clinical question:
– “Is carvedilol an effective treatment for congestive heart failure?”
• Concepts to use while searching for information:
– Congestive heart failure, carvedilol
PICO
• PICO – a structure used to formulate evidencebased questions
– Example for today uses congestive heart failure
P
Problem/Patient
Congestive heart failure (CHF)
I
Intervention
Beta blocker (carvedilol)
C Comparison (optional)
None (might consider metoprolol)
O Outcome
Various things you might measure:
--Quality of life
--Mortality
--Hospitalization
--Cost
EBM INFORMATION
RESOURCES
Background Resources
• Clinical Information Tools
–
–
–
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Essential Evidence Plus
ACP Pier
UpToDate
Clinical Evidence
EBM Databases
From Ovid:
• Cochrane Database of Systematic Reviews
o Mentioned by Dr. Samet
o A collection of Systematic Reviews created by the Cochrane Collaboration
• ACP Journal Club
o Selected “original studies and systematic reviews”
o “Warrant immediate attention by physicians”
o What you see is an abstract of the article and commentary “by clinical experts”
o Evaluate methodology and results
• Database of Abstracts of Reviews of Effects (DARE)
o “DARE …systematically identifies and quality assesses reviews from around
the world.”
“Change database” and “Open and Re-execute” allow rapid search
of all three sources
MEDLINE (OvidSP)
– MEDLINE with filters
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•
•
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Systematic review “subject subset”
Meta analysis “limit”
RCT “limit”
Cohort “MeSH”
Case control “MeSH”
EBM Aggregator and Guidelines
– TRIPdatabase
– Sources of guidelines
• National Guideline Clearinghouse -- (US)
• National Institute for Health and Clinical Excellence
(NICE) – (UK) – mentioned by Dr. Samet
Conclusion
• We have touched on:
– the EBM process
– Evidence pyramid and Levels of Evidence
– PICO
– Places to find evidence-based information
•
•
•
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Background resources
EBM databases
MEDLINE with EBM “filters”
TRIP and sources for guidelines
Last Slide
• All materials from this session will be posted
on Year 2 KSOM library portal page
• Please fill out class evaluations
• Contact your personal librarian (or any of us)
for questions about any of this
• Thanks!