Evidence Based Medicine and Keeping Up With the
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Transcript Evidence Based Medicine and Keeping Up With the
Using the Internet to Practice EvidenceBased Dermatology
David A. Barzilai, M.D., Ph.D.
Brown University
Department of Dermatology
Presentation Home: http://ebderm.org
Last Update: 1.9.07 (check http://ebderm.org for latest updates)
Presentation Objectives
This Presentation Addresses:
What is Evidence-Based Medicine (EBM)?
How does one practice EBM?
What tools are available to practice EBM?
– Emphasis on internet tools (available at http://ebderm.org)
– Special resources of dermatological interest will be highlighted
Evidence-Based Medicine
"the conscientious, explicit, and judicious use of
current best evidence in making clinical
decisions about the care of individual patients."
– Dr. David Sackett, “father” of EBM
EBM is not “cookbook medicine”
Evidence is thoughtfully integrated w/:
– Patient preferences
– Provider expertise (including knowledge what makes
this patient unique)
Setting
The Goal: Providing exemplary care for our patients,
using the current best evidence
The Challenge:
– Minutes per patient encounter to seek out best evidence
– Minutes to hours per week of reading to “stay current”
– Research data is accruing faster than our ability to read!
The Issue: how do we best make use of our limited
time for:
– Information retrieval and “reading time”
– Information management
– Evidence-based medical practice
Overview: EBM Search Algorithm
1.
Formulating a well-built clinical question
2.
Finding the current best evidence*
3.
Critically appraising the evidence for validity
4.
Application of this evidence, integrating the data with
patient values and clinical expertise.
5.
Storing the data and evaluating performance of steps 14 for continuous quality improvement
* We emphasize step 2 in this brief presentation
The Well-Built Clinical Question
Includes the following (P.I.C.O.):
1.
2.
3.
4.
A Patient or population
An Intervention or “exposure”
A Comparison intervention (if appropriate)
A clinical Outcome (diagnosis/screening, prognosis,
therapy, event, harm, or prevention)
Well-Built Clinical Question (WBCQ) – an
Example
“In a 22 year old woman with mild noncomedonal acne (Patient), does monthly use of
salicylic acid (Intervention) or benzoyl peroxide
(Comparison) prevent more acneiform lesions
from developing (Outcome)?” Resources to
facilitate WBCQ’s
The WBCQ- Resources
Anatomy of a well-built clinical question (University of Sheffield)
Contstruct a well-built clinical question using PICO (University of
Washington)
Further reading on well-built clinical question, from University of
Medicine and Denistry of New Jersey.
Sackett et. al (see References)
When you have created your well-built clinical question, consider
using this as the basis for contributing a Critically Appraised Topic to
ebderm.org, which is a practice-based learning tool for conducing
evidence-based searches and evaluations.
What Kind of Study to Answer my
Question?
Keep in mind the Hierarchy of Evidence:
– Systematic review of RCTs > RCT>Cohort>xsectional >case report> anecdote (“rule of thumb”)
– However, a good observational study beats a poorly
conducted Randomized Controlled Trial (RCT).
Also, the best design varies by the question:
– Prognosis, harm: Cross Sectional or Cohort Study
– Natural history, Diagnosis: Cohort Study
– Therapy & prevention, other interventions: RCT’s
Critically Examine All Sources
Foundation is epidemiology and biostatistics
– Is this study important?
– Is this study valid?
– Does this study apply to my patient population?
Learn Critical Appraisal Skills (free):
– Synopsis of JAMA review of EBM
– University of Alberta EBM Toolkit
– Basic Biostatistics 1 and Basic Biostatistics 2 (BMJ)
Seeking the Evidence (overview)
Evidence-Based Resources:
1.
2.
3.
4.
Evidence-Based Systematic Review Databases
Secondary journals
EBM textbooks and guidelines
Medline / electronic databases
Consult Medline first for very latest research
What About Consulting Colleagues and
Experts??...
Image source: http://www.askanexpert.com/
Least Reliable Sources of Evidence
Colleagues, experts, & “throw-away” journals
– Convenient and fast
– Often invalid , incomplete, and biased information
Textbooks (usually)
–
–
–
–
Generally not systematically researched
Usually based on “expert opinion”
Most are out of date - check for recent citations
Great exception (explicit protocols):
1. Evidence-Based Systematic Review
Databases
Traditional narrative reviews are often expert-based,
biased, and incomplete (unreliable).
Systematic reviews are characterized by:
–
–
–
–
Clear and focused study question
Explicit definition of study criteria to be included
A priori protocol for collating the evidence
Exhaustive search, including“hand-searching” and
unpublished studies
– Explicit or implicit factoring of study quality
Most comprehensive resource for therapy Q’s
Systematic Review Databases
The Cochrane Library :
– Best source for structured, systematic reviews
– Explicit search & quality criteria (free abstracts)
Database of Abstracts of Reviews of Effectiveness
(DARE)
– Structured abstracts of systematic reviews meeting highest
quality standards
– A (free) part of the Cochrane Library
Evidence-Based Medicine Reviews (EBMR) integrates
the above with secondary journal content:
– ACP Journal Club / Best Evidence
– Medline searching and some full-text journals.
2. Secondary Journals
Evidence-Based “secondary journals” provide structured
abstracts with balanced commentary
Selected from high quality publications
Can be best resource to start with when investigating rare
clinical conditions (saves time).
E.g.’s– Evidence-Based Medicine, ACP Journal Club (free)
– Specialty-specific resources: Evidence-Based Dermatology
section of Archives of Dermatology
– Bandolier (free) brief EBM summaries of summaries
Journal Watch Dermatology, a product of the publishers of
the New England Journal of Medicine, provides month
summaries with expert commentary for 13-15
manuscripts.
3. EBM Textbooks
Most efficient source for simple clinical queries, but
most quickly outdated
– Evidence-Based Dermatology the definitive book on evidence-based
dermatology (link to review).
– Clinical Evidence, by BMJ Publishing Group and ACP, meets the highest
evidence-based medicine standards.
– UpToDate meets a high standard of evidence-based content and
periodically updated.
– ACP Medicine, developed from WebMD Scientific American®
Medicine available online by subscription.
Evidence-Based Guidelines
The best sources rate the strength of evidence
Always consider external validity to your patient
– The National Guideline Clearinghouse is the most well known of the high
quality clinical guideline databases (free).
– The Guide to Clinical Preventative Services includes the latest clinical
prevention recommendations by the U.S. Preventive Services Task
Force (free)
– The UK National Electronic Library for Health Guidelines has over 2000
guidelines produced in the United KIngdom (free).
– The Guidelines International Network permits guideline searches with a
more international focus with membership.
– For skin-related guideilnes developed through by two large dermatology
associations, you can visit the American Academy of Dermatology
guidelines and the British Association of Dermatologists guidelines.
4. Medline
If the Cochrane Library has not addressed our question, next try
Medline…
The largest biomedical literature database, but:
– Misses some journal articles, misclassifies others
– Can be overwhelming if not searching selectively
PubMed is a free Medline service with Boolean and other
search capabilities.
Sample PubMed queries can be found at Sample Clinical Query
(from the New York Academy of Medicine) (free)
Clinical query filter facilitates clinical searches
Medline searching tips from the New York Academy of Medicine
helps you take advantage of the power of Medline (free)
Meta-Search Engines
Permit integrated multi-source searches
– Evidence Based Medicine Reviews, by Ovid:
searches Cochrane, DARE, ACP Journal Club, and
Medline.
– Tripdatabase: Cochrane Library, DARE, the National
Guideline Clearinghouse, clinical questions answering
services, online books, and Medline
Quality more variable
– SUMSearch: Cochrane, National Guide
Clearinghouse and other sources
Incorporates data quality in results.
Critically Appraised Topics (CATs)
Practice-based learning of EBM
Results vary by author, source
– Ebderm.org will host an international CAT bank specific to skin
disease.
– Spanish Language dermatology CAT bank available at
dermatoscopio.cl
– BestBets
– The CAT Bank
– CAT Crawler is a search engine for CATs from multiple sources,
but currently does not search ebderm.org or dermatoscopio.cl for
skin-related CATs.
Information Management
Use Science Citation Index to search for newer
articles that cited an older classic paper of interest.
EMBASE is a Medline alternative
– More extensive European journal representation
– Wider array of health science disciplines represented
Invest in a citation manager program such as
EndNote:
– Download abstracts from Medline
– Label abstracts for quick searches later
– Effortless reference resorting
Guidelines for Reading
Choose 2-3 gold standard journals relevant to
your patients for weekly reading
Devote weekly protected time for reading
Subscribe to e-mail TOC’s of 1-3 other high
quality journals (e.g. Lancet, JAMA).
Consider specialty-specific services:
– Dermlinx (www.mdlinx.com)
– Medscape Dermatology (www.medscape.com)
Selected Comprehensive Web-Based EBD
Resources
Evidence-Based Dermatology
Centre for Evidence-Based Dermatology
Netting the Evidence
Centre For Evidence Based Medicine
Evidence-Based Medicine Resource
Center
Some Final Suggestions
The most effective way to learn evidencebased dermatology is to practice it:
– Consider creating a Critically Appraised Topic
(CAT) on ebderm.org
Consider joining IDEA (International
DermatoEpidemiology Network)
Get involved with the Cochrane Skin Group
Distribution Statement
You may distribute freely, provided that
this presentation is preserved in its
entirety without changes
Questions / comments:
– David A. Barzilai, MD PhD (skinresearch.org)
– For presentation updates see: ebderm.org
References
Arndt KA: Information excess in medicine. Overview, relevance to
dermatology, and strategies for coping. Arch Dermatol 128:1249-1256, 1992
Barzilai DA, Freiman A, Dellavalle RP, Weinstock MA, Mostow:
Dermatoepidemiology. J Am Acad Dermatol. 2005 Apr;52(4):559-73; quiz
574-8 [CME Review].
Bigby M: Evidence-based medicine in dermatology. Dermatol Clin 18:261276, 2000 (much like the above – choose one)
The Challenge of Dermato-epidemiology by Hywell Williams (Book)
Cook DJ, Meade MO, Fink MP: How to keep up with the critical care
literature and avoid being buried alive. Crit Care Med 24:1757-1768, 1996
Evidence-Based Medicine: How to Practice and Teach EBM by David
Sackett
How to Read a Paper: The Basics of evidence based medicine by Trisha
Greenhalgh
Studying a Study and Testing a Test by Richard Riegelman and Robert
Hirsch