2. Evidence based medicine By: Mohsen Dehghani MSc Student in Epidemiology Isfahan University of Medical Sciences 1

3. Trace back to the development of EBM

4. Evidence based medicine تلفیق بهترین شواهد بدست آمده از تحقیق با مهارتهای کلینیکی و ارزشهای بیمار. David Sackett, et al. 2000 استفاده دقیق، روشن و عاقلانه از بهترین شواهد موجود برای تصمیم گیری در مورد مراقبت از یکایک بیماران. Best Evidence Patient values Clinical expertise 3

5. Evidence based medicine Evidene based practice (EBP) چرا به EBP نیاز داریم؟ 4

6. Evidence based medicine Archei cochrane, British epidemiologist, 1972 او در سال 1979 نوشت : ” مطمئنأ انتقادی بزرگ از حرفه ما این است که برنامه ای برای خلاصه کردن منظم و منتقدانه همه کارآزماییهای بالینی مربوط به یک موضوع در رشته های تخصصی و فوق تخصصی مختلف و بازبینی مستمر آنها نداریم.“ Cochrane center Cochrane collaboration Cochrane library 5

7. استفاده از کورتیکوستروئیدها در زایمان زودرس RCT-1972 6RCT, 1972 – 89 Systematic review, 1990 conclusion 6

8. Push, Pull, …ways to deal with too much information Evidence-Based Information Resources 7

9. Increasing Knowledge 8

10. The steps 1. answerable questions 2. Find the best evidence 3. Critically appraise that evidence for its validity and usefulness 4. Apply the results 5. Evaluate the performance 9

11. A cquire the best evidence A ppraise the evidence A pply evidence to patient care A ssess your patient A sk clinical questions EBM Method 10

12. Where Clinical Questions Arise From: Clinical findings Aetiology: Differential diagnosis: Diagnostic tests: Prognosis: Therapy: Prevention: 11

13. Question components : PICO What types of P articipants? What types of I nterventions? What types of C omparison? What types of O utcomes? 12

14. The four elements of well built clinical questions: (PICO) Patient Or problem InterventionComparison intervention outcome Tips for building Starting with your patient ask “how would I describe a group of patients similar to mine?” Ask: “Which main intervention am I considering?” Ask “What is the main alternative to compare with the intervention?” Ask “What can I accomplish?” or “What could this exposure really affect?” example In healthy 1 year old infants Does giving combined MMR vaccine When compared to not giving Lead to increased incidence of autism? 13

15. Best Evidence… Journal of evidence based medicine. Encyclopedia of clinical evidence 14

16. The Evidence Pyramid Time Spent in Critical Appraisal Validity /Strength of Inference 15

17. Finding the Evidence systematic review 16

18. Systematic review & Meta-analyses تاثیر دریافت مواد غذایی در طول زایمان بر پیامد مادری زنان باردار: RCT ارتباط بین چاقی و سکته مغزی درمان با انسولین و خطر ابتلا به سرطان 17

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20. PubMed Clinical Queries 19

21. PubMed Clinical Queries 20

22. PubMed – Key Features Clinical Queries –Clinical study by category –Find systematic reviews MeSH Database –Synonyms (keywords) to use for your searches –Tutorials Comprehensive Limits Option “My NCBI” Alert, Storage and Retrieval Option 21

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24.  The Cochrane Collaboration Preparing, maintaining and disseminating systematic reviews of the effects of health care 23

25. Cochrane Library International collaboration Produces systematic reviews and meta- analyses of individual studies DARE Registry for RCT Updated regularly Abstracts are free http://www.cochrane.org 24

26. The Cochrane Library Total Records at December 2010 DatabaseTotal Records The Cochrane Database of Systematic Reviews (Cochrane Reviews) 6447 Database of Abstracts of Reviews of Effects ( DARE ) 13521 The Cochrane Central Register of Controlled Trials (CENTRAL) 635,167 The Cochrane Methodology Register (Methodology Register)13,721 Health Technology Assessment Database (HTA)8908 NHS Economic Evaluation Database (NHS EED)28,991 About The Cochrane Collaboration and the Cochrane Collaborative Review Groups (About)80 25

27. 3. Critically appraise that evidence for its validity and usefulness 3. Critically appraise that evidence for its validity and usefulness 1- pico مطالعه چیست و آیا کاملأ مشابه pico شماست؟ 2- مطالعه چقدر خوب انجام شده است؟ 3- نتایج چه معنی می دهند؟ 26

28. What is critical appraisal? Critical appraisal is the assessment of evidence by systematically reviewing its relevance, validity and results to specific situations. Chambers, R. (1998). 27

29. Three questions Valid? Is the methodology appropriate to answer the question. Is it carried out in a sound way, eliminating bias and confounding? Reliable? Are the results real or because of chance? Applicable? Will the results help locally? 28

30. 29 Dealing with chance error During design of study – Sample size – Power During analysis (Statistical measures of chance) – Test of statistical significance (P value) – Confidence intervals

31. 30 95% Confidence Interval (95% CI) 20 out of 100 participants: 20% 95% CI: 12 to 28 80 out of 400 participants: 20% 95% CI: 16 to 24 2000 out of 10000 participants: 20% 95% CI: 19.2 to 20.8

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33. 32 Quality assessment tools Checklist : the components are evaluated separately and do not have numerical scores attached to them Scale: each item is scored numerically and an overall quality score is generated.

34. 4. Apply the results آیا تست یا درمان مورد نظر در بیماران مرکز طبابت من قابل انجام است؟ آیا بیماران من متفاوت از افرادموجود در مطالعه است که منجر به عدم کاربرد نتایج میشود؟ آیا روش دیگری در دسترس است؟ آیا فواید بالقوه درمان بیش از زیانهای بالقوه آن برای بیمار من است؟ بیمار من در این مورد چگونه فکر میکند؟ 33

35. Think اگر دانشجوییم وظیفه ما جستجوی علم و رعایت ادب و احترام استاد و... وظیفه ما این است که عمل به وظیفه کنیم ” Leonardo Davinchi“ 34

36. References Paul glasziou, Chris Del Mar. Evidence-Based Practice workbook. University of Oxford; 2008 Sackett DL, et al. Evidence Based Medicine: How to practice and teach EBM. Edinburge; 2000 Glasziou P. Evidence based case report: Twenty year cough in a non-smoker. British Medical Journal 2006. http://www.cvidene-evidence-based medicine.comhttp://www.cvidene-evidence-based http://www. Cochrane.orghttp://www Bero L, Rennie D. The Cochrane Collaboration. JAMA 2007 ;274:1935–8. http://www.CONSORT-sratement.org/revisedstatement.htm.Vol.9 No.1, March 2007http://www.CONSORT-sratement.org/revisedstatement.htm.Vol.9 No.1 35