Evidence-Based Medicine Ambulatory Care Block 2008-2009 Course Introduction John H. Choe, MD, MPH

1. Evidence-Based Medicine Ambulatory Care Block 2008-2009 Course Introduction John H. Choe, MD, MPH Jenny Wright, MD Scott Steiger, MD Sherry Dodson, MLS

2. Course Leaders • John Choe, MD, MPH, Acting Assistant Professor • Harborview Medical Center, Adult Medicine Clinic • johnchoe@u.washington.edu • Sherry Dodson, MLS, Clinical Medical Librarian • UWMC Health Sciences Library • sdodson@u.washington.edu • Jenny Wright, MD, UWMC Ambulatory Chief Resident • sonic@u.washington.edu • Scott Steiger, MD, HMC Ambulatory Chief Resident • steiger@u.washington.edu

3. Introductions • Name • College major and medical school • Home clinic • Fun fact that others don’t know • Prior experience with epidemiology, biostatistics, research or research design • “My goal in a class on evidence-based medicine would be to learn ___”

4. What is Evidence-Based Medicine? Evidence-based medicine is the integration of the best available research evidence with clinical expertise and patient values. From Straus, Richardson, Glasziou, Haynes. “Evidence-Based Medicine: How to practice and teach EBM”, 3rd Edition

5. Steps to Practicing EBM • Convert the need for information into an answerable question. • Track down the best evidence with which to answer that question. • Critically appraise the evidence for its validity, impact, and applicability. • Share this evidence with our colleagues and our patients. 5. Integrate the evidence with our clinical expertise and our patient’s characteristics and values. Adapted slightly from Straus, Richardson, Glasziou, Haynes. “Evidence-Based Medicine: How to practice and teach EBM”, 3rd Edition

6. Syllabus • Wk 1: Intro to course and computer resources • Wk 2: RCT • Wk 3: Meta-analyses and systematic reviews • Wk 4: Computer search strategies in practice • Wk 5: Cohort and case-control studies • Wk 6: Cost-analysis and qualitative studies • Wk 7&8: resident article presentations

7. Course Expectations • Each resident will summarize one “classic” and one “new” article • “Classic” articles will be presented during weeks 2-6 • “Classic” articles can be chosen from the provided list, or another if discussed with course leaders first • “Classic” articles are used primarily as examples of different types of study design, and secondarily to learn their content • Each resident will review the “classic” articles being presented by their peers each week (10 min.) • “New” articles will be presented during weeks 7-8 • “New” articles (<3 yrs) will be based on question of interest, using search strategy developed with Sherry Dodson • Resident presentations of “new” articles (10 minutes, plus 15 minutes of questions and discussion)

8. Today’s Topics How to triage and skim medical literature quickly & efficiently Brief overview of study design types Designing answerable clinical questions Introduction to literature search strategies Brief introduction to RCTs Volunteers for next week’s “classic” article presentations

9. Usual Article Format Title, authors Look for institutions and funding information Abstract: Structured or unstructured Background/ Introduction/ Objective Design/ Methods/ Statistics and analysis plan Results Tables and Figures: Table 1– Usually comparing study groups to one another Figure 1– Sometimes recruitment or design plan Often one “money” table or figure of key results Conclusions/ Discussion/ Implications References

10. How to Skim Articles– First Steps • Journal is important in deciding if articles are worth reading • Don’t try to read everything in an article in order! • Title: Most skip ~80-90% of articles based on title alone

11. How to Skim Articles– Abstract • Abstract: Background– Does the question/ problem interest me? • Abstract: Conclusion– Does this look like a study that might change my practice? • Abstract: Methods– Does the study design and population studied appear to be appropriate?

12. How to Skim Articles– Design/Results Tables– Does “table 1” appear to reflect my patients? Figures– Does “figure 1” appear to accurately report inclusion/ exclusion/ drop-outs/ etc? Figures– Do the results appear to be statistically significant? Conclusion– Do the results appear to be clinically important? Once you have satisfied yourself that the article contains “read-worthy” material, THEN spend the extra time to read it in depth.

13. Evidence Pyramid pyramid modified from: Navigating the Maze, University of Virginia, Health Sciences Library

14. Alternative View of Study Design Descriptive Studies Hypothesis-generating Analytic Studies Hypothesis-testing • Case report/ case series • Descriptive epidemiology Intervention Studies • Qualitative studies • Quasi- • experiments • Randomized trials Observational Studies • Cost-benefit/ -effectiveness • Case-control • Cohort • Cross-sectional • Meta-analyses • Retrospective • Prospective Adapted from Kopesell & Weiss. Epidemiologic Methods: Studying the occurrence of illness

15. Example Case • Mr. S is your 65-yo Filipino male with past history significant for ischemic stroke. On exam in your office, he has stable old mild residual weakness of his right arm and leg, and has bilateral carotid bruits. • In managing your patient, you have sent him for carotid duplex scan and learned that he has moderate (50-69%) stenosis of the internal carotid artery. • What questions can you formulate to help manage his care in an evidence-based manner?

16. The nature of the question asked is experience- dependent. SPECIFIC KNOWLEDGE TYPE OF QUESTION GENERAL KNOWLEDGE CLINICAL EXPERIENCE

17. Well-Built Clinical ?’s Directly relevant to the patient’s care and our knowledge deficit. Contains the following elements: P: the patient or problem being addressed I: the intervention or exposure being considered C: the comparison intervention or exposure, when relevant O: the clinical outcomes of interest. “Intervention” may be an exposure to a factor; a diagnostic test under consideration; a prognostic factor; a drug or other therapy; patient belief or knowledge; etc. “Comparison” is most relevant for trials of therapy

18. Example: Specific Well-Built Clinical ?’s “Can ASA decrease the risk of stroke?” PICO Patient or problem being addressed: Intervention or exposure being considered: Comparison intervention or exposure: Clinical Outcome of Interest:

19. Example: Specific Well-Built Clinical ?’s “Can ASA decrease the risk of stroke?” PICO Patient or problem being addressed: 65 yo with past stroke and moderate carotid stenosis Intervention or exposure being considered: Aspirin Comparison intervention or exposure: Placebo Clinical Outcome of Interest: Future stroke “In a 65 yo man with history of past stroke and with moderate carotid stenosis, can ASA decrease risk of recurrent stroke compared to placebo?”