EBM for Novice

1. EBM for Novice Maria Kwok, MD, MPH Assistant Clinical Professor Section of Pediatric Emergency Medicine Morgan Stanley Children’s Hospital of New York Presbyterian

2. Outline • Why is EBM important? • What is EBM • Understand foreground vs. background questions • Formulate PICO questions • Find resources, do searches • Validity of an article • Appraise “Therapy” articles • Appraise “Diagnostic” articles

3. Why is EBM Important? • MEDLINE • 400,000 new entries added each year • To keep up-to-date • Need to read 6,000 articles each day

4. Why is EBM Important? Lag time from time of “knowing” to time of “implementation” • 13 years for thrombolytic therapy • 10 years for corticosteroids for acceleration of fetal lung maturity (Antman EM, JAMA, 1992)

5. Traditional Approaches Self-reported reading time per week. (University setting) • Medical students 60 min. • Interns none • Senior residents 10 min. • Fellows 45 min. • Attendings graduating • Post 1975 60 min. • Pre 1975 30 min.

6. There is simply no way we can keep up to date in medicine using traditional approaches!

7. Outline • Why is EBM important? • What is EBM? • Understand foreground vs. background questions • Formulate PICO questions • Find resources, do searches • Validity of an article • Appraise “Therapy” articles • Appraise “Diagnostic” articles

8. Quiz: Define EBM A) A means of camouflaging biostatistics in medical training B) An annoying and overused catch phrase C) The conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients

9. Research Evidence Decision Making Patient Preference Clinical Expertise

10. Evidence Based Medicine: A Process Patients Ask Questions Appraise Searching

11. Validity Results Applicability

12. Outline • Why is EBM important? • What is EBM • Understand foreground vs. background questions • Formulate PICO questions • Find resources, do searches • Validity of an article • Appraise “Therapy” articles • Appraise “Diagnostic” articles

13. What’s the difference between foreground and backgroundquestions?

14. Asking the Precise Question • Background questions • Basic aspect of a disease • Pathophysiology • Etiology • Basic treatment • Who, what, when, how • Foreground questions • Specific knowledge • Have 4 parts: • Patient/problem • Intervention • Comparison intervention • Clinical outcomes

15. Background or Foreground? • What is asthma? • Is prednisone helpful in asthma? • What are the newest medication for asthma? • Does atrovent used acutely make you feel better?

16. Background or Foreground? • What is asthma? (B) • What are the newest medication for asthma? (B) • Does atrovent used acutely make you feel better? (F) • Is prednisone helpful in asthma? (F or B) • Foreground if compare to other drugs • Background if interested in how it works

17. Outline • Why is EBM important? • What is EBM • Understand foreground vs. background questions • Formulate PICO questions • Find resources, do searches • Validity of an article • Appraise “Therapy” articles • Appraise “Diagnostic” articles

18. Structure of a Well-built Question • Patient or population • Be specific to capture the group you want • Ex: Children w/ asthma • Intervention • Be specific • Comparison group (if any) • Compare to standard therapy or test • Outcome • Be precise • What are the outcome of interest

19. Formulating the Clinical Question PICO

20. Can You Identify PICO? • In children under 6 months, how does sleeping on back compared to sleeping on the stomach in terms of risk of SIDS? • In children under 6 months (P), how does sleeping on back (I) compared to sleeping on the stomach (C) in terms of risk of SIDS (O)?

21. Can You Form a PICO Question? Clinical scenario: 5 yo with moderate persistent asthma now in severe acute asthma exacerbation. Intern gave 2 albuterol and orapred with minimal improvement. Intern asks why how good is atrovent?

22. Searchable PICO Question P: Population I: Intervention/diagnostic test/risk factor C: Comparison O: Outcome In children with acute asthma exacerbation (P), will the addition of atrovent (I) to albuterol (C) decrease the rate of hospitalization (O)?

23. Outline • Why is EBM important? • What is EBM • Understand foreground vs. background questions • Formulate PICO questions • Find resources, do searches • Validity of an article • Appraise “Therapy” articles • Appraise “Diagnostic” articles

24. Searching Superhero Best Bets

25. The Evidence Pyramid

27. Pre-appraised Resources • Cochrane • http://www.cochrane.org/cochrane/revabstr/mainindex.htm • Very high quality reviews • Mostly questions of therapy • National Guideline Clearinghouse • http://www.guideline.gov/ • Guidelines of varying levels of quality • Do broad searches • PEM database • http://researchinpem.homestead.com/homepage.html • Not pre-appraised

28. Pre-appraised Resources • Best Evidence Topics • http://www.bestbets.org • Developed in the ED of Manchester Royal Infirmary in UK • Usually EM topics • Free • Clinical Evidence (CE Concise) • http://www.clinicalevidence.com • From UK • Focus mostly on therapy • Free

29. Primary Search Engines • Pubmed • Ovid

30. Primary Search Engines • Both PubMed and Ovid • Contains MEDLINE and other bibliographic databases (Cochrane, EMBASE, etc) • Sells access to the databases to libraries

31. PubMed MEDLINE vs. Ovid MEDLINE • Same DATABASE • Different SEARCH ENGINES • Searching differently may get you slightly different results • If you search both databases EXACTLY the same, your results will be the same

32. What is MEDLINE? • MEDLINE is a DATABASE • MEDLINE is produced by the National Library of Medicine • MEDLINE is available free via Pubmed • MEDLINE is sold to many vendors, like Ovid, who search the DATA in MEDLINE through different search engines

33. Database Producer Vendors Medline EMBASE CINAHL Ovid Pubmed Dialog LEXIS/NEXIS Personal PC Library PC

34. PubMed: Clinical Queries • Pre-filtered searching • Search on questions of • Therapy • Diagnosis • Etiology • Prognosis • Or, search for Systematic Reviews Limit any of the categories to sensitivity (broad) or specificity (narrow)

38. Sensitivity vs. Specificity • SPECIFICITY • Narrower search • More relevant items • Possibility of losing some useful citations • LESS information to weed through • SENSITIVITY • Broader search • More irrelevant items • Less chance of losing useful citations • MORE information to weed through

43. OVID • Most librarians favor this search engine • Allow you to tailor your search

45. Design & Execute Search Strategy • MeSH terms • How articles are indexed • Predefined categories from the National Library of Medicine • Explode • MeSH + all items underneath • Focus • MeSH only

46. Design & Execute Search Strategy • Limiters • Limit by languages, human, age, etc • Hedges • “Clinical trials” for therapy • “Sensitivity” & “Specificity” for diagnostic tests • “Cohort studies” for prognosis

47. More on Searching Tips • “Term$” • Search engines will look for occurrences of the word with any combination of letters following. (Ex: “Hospital$” will include hospitalization, hospitals, hospitalized) • “Exp” for “explode” • “Term.tw.” • Allow search engine to look in the titles and abstract

48. More on Searching Tips • “Term.af” • Search all fields • “..pg term” • Perge/delete

49. For More Searching Tips Ask your librarians!

50. Outline • Why is EBM important? • What is EBM • Understand foreground vs. background questions • Formulate PICO questions • Find resources, do searches • Validity of an article • Appraise “Therapy” articles • Appraise “Diagnostic” articles