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Existing knowledge can prevent… Waste Errors Poor quality clinical care Poor patient experience Adoption of interventions of low value Failure to adopt.

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Presentation on theme: "Existing knowledge can prevent… Waste Errors Poor quality clinical care Poor patient experience Adoption of interventions of low value Failure to adopt."— Presentation transcript:


2 Existing knowledge can prevent… Waste Errors Poor quality clinical care Poor patient experience Adoption of interventions of low value Failure to adopt interventions of high value Source: Sir Muir Gray, Chief Knowledge Officer of Britain’s National Health Service. Quoted on

3 Learning Objectives At the end of the presentation, you will be able to: Define evidence-based medicine (EBM) Understand the Five Steps to practice EBM Use the 4S approach to organizing clinical research evidence Conduct an efficient online search to track down best evidence Access online and print tools to critically appraise the evidence Use the Five Steps for research and clinical care

4 “Evidence-based medicine is the integration of best research evidence with clinical expertise and patient values” Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS: Evidence based medicine: what it is and what it isn’t. BMJ 1996;312:71-2. Patient Concerns Clinical Expertise Best research evidence EBM What is EBM?

5 Evolution of EBM in the Literature Term first appeared in the literature in a 1991 editorial in ACP Journal Club Volume 114, Mar-April 1991, pp A-16 Seminal article by the Evidence-Based Medicine Working Group published in JAMA Volume 268, No. 17, 1992, pp 2420-2425

6 Fundamentally new approach becomes widely recognized JAMA published a series of Users’ Guides to the Medical Literature that served as the first learning tools Courses were developed in residency training and medical school curricula The first handbook, Evidence-Based Medicine: How to practice and teach EBM, by Sackett, et al, was published in 1996. Fourth edition published in 2010. New York Times listed EBM as one of its ideas of the year in 2001 BMJ listed EBM as one of the 15 greatest medical milestones since 1840

7 New Approach Required New Skills Clinical question formulation Search and retrieval of best evidence Critical appraisal of study methods to ascertain validity of results

8 Integration of EBM into medical school curricula patient-doctor courses

9 Key developments that streamlined the practice of EBM Advances in ease of accessing and understanding information Development of preprocessed (preappraised) tools Improvements in search interfaces to MEDLINE Collaboration between EBM Working Group and National Library of Medicine in development of hedges, “clinical queries” tool, that filters search results to specific study types and levels of evidence Dissemination of systematic reviews of primary studies and growth of the Cochrane Collaboration

10 EBM Process – 5 Steps 1. ASSESS: Recognize and prioritize important patient problems 2. ASK: Construct clinical questions that facilitate an efficient search 3. ACQUIRE: Track down the best evidence to answer the questions 4. APPRAISE: Systematically evaluate best available evidence for validity, importance, and usefulness 5. APPLY: Interpret the applicability of evidence to specific problems, given patient preferences and values

11 4S Hierarchy

12 6S Hierarchy

13 4S Examples  Point of Care Summaries: Uptodate, Dynamed, FIRSTConsult  DARE (synopses of syntheses)  ACP Journal Club (synopses of studies) Cochrane and other Systematic Reviews  Clinical Key Searches Limited to Study Types, MEDLINE Searches limited to Clinical Queries SOURCE: Haynes, R. B. (2001). Of studies, syntheses, synopses, and systems: the “4S” evolution of services for finding current best evidence. Evidence-Based Medicine, 6 (2), 36-38. Retrieved 2-07-07 from

14 Critically Appraised Content

15 Evidence Based Retrieval 1.Find the answer that is supported by valid studies appropriate to the type of question and that is available in a timely manner. 2.Requires search terms plus best study design for question plus highest level of evidence

16 Extract search terms from question Therapy/Prevention Question in PICO  In patients with primary open angle glaucoma or ocular hypertension [Patient/Population], do topical medications to reduce intraocular pressure [Intervention] versus no treatment [Comparison Intervention], delay visual field defect progression [Outcome]?

17 Possible Search Terms Ocular hypertension, OHT, intraocular pressure, IOP, primary open angle glaucoma, POAG, medical treatment, medical intervention, visual fields, VF

18 As you move up the pyramid the amount of available literature decreases, but it increases in its relevance to the clinical setting. Source: Sackett, D.L., Richardson, W.S., Rosenberg, W.M.C., & Haynes, R.B. (1996). Evidence-Based Medicine: How to practice and teach EBM. London: Churchill-Livingstone.

19 Best Study Design for Type of Question Type of QuestionStudy Design Therapy/preventionRandomized controlled trials DiagnosisProspective cohort, blind comparison to a gold standard PrognosisCohort, Case Control, Case Series Etiology/HarmCohort, Case Control, Case Series

20 Systems/Summaries DynaMed –Summaries for more than 3,000 topics –Monitors >500 medical journals and systematic review databases –Updated daily –Each article evaluated for clinical relevance and scientific validity –Includes “graded evidence”

21 Glaucoma Summary Evidence-based answer found in 1 minute, 39 seconds

22 Systems/Summaries UptoDate –Evidence based summaries of over 9,500 topics in over 20 specialties –Ophthalmology not one of the specialties –Good for information on systemic conditions –Available through individual subscription. Online access plus Mobile app for iPhone and iPad. Cost: $199 per year in training; $499 per year in practice

23 Syntheses Cochrane Database of Systematic Reviews (DSR) –Part of the Cochrane Library (1996) –916 completed reviews, 1905 protocols –Among the highest level of evidence upon which to base treatment decisions –Includes Dx since 2008 –Eyes & Vision Research Group Contains over 165 reviews

24 Systematic Review Analyzes data from several primary studies to answer a specific clinical question Provides search strategies and resources used to locate studies Includes specific inclusion and exclusion criteria (results in less bias) Meta-Analysis (subclass) statistically summarizes results of several individual studies Access full text of Cochrane reviews in OVID

25 Review found in 15 seconds Cochrane DSR

26 Copyright: The Cochrane Library, Copyright 2009, The Cochrane Collaboration

27 Levels of Evidence Grade the quality of evidence based on the design of the clinical study Variety of hierarchies in use

28 DynaMed

29 Levels of Evidence in Ovid based on AAFP SORT  Level A = “Specificity” in Ovid Clinical Queries Systematic reviews of randomized controlled trials including meta- analyses Good-quality randomized controlled trials  Level B = “Sensitivity” in Ovid Clinical Queries Good-quality nonrandomized clinical trials Systematic reviews not in Level A Lower-quality randomized controlled trials not in Level A Other types of study: case control studies, clinical cohort studies, cross sectional studies, retrospective studies, and uncontrolled studies  Level C Evidence-based consensus statements and expert guidelines

30 Appraisal Required by User

31 Primary (Original) Studies Articles that report results of original research investigations Conclusions supported by data and reproducible methodology Require time to acquire and appraise Good Sources: MEDLINE and Clinical Key

32 When to search for original studies If the other “S’s” don’t provide the answer, search for original studies Appraise best available evidence or find analysis in evidence based resource Use “clinical queries” limit in Ovid MEDLINE Limit to “Study Type” in Clinical Key Least efficient (in terms of time)

33 Take Home Points Focused clinical question (PICO) reveals your search terms Start your search at top of 4S hierarchy and work down Be aware of the filter, i.e., levels of evidence, speed of updating Look at more than one resource in the hierarchy. Findings may differ Practice makes perfect


35 Evidence Based Medicine Lecture Sandra A. Martin, M.L.I.S. Health Sciences Resource Coordinator Instructor of Library Services John Vaughan Library Room 305B – 918-444-3263

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