1. Evidence Based Medicine Critical Appraisal 高雄榮民總醫院 臨床訓練中心 實證醫學組 台灣實證醫學學會 徐圭璋

2. 實證醫學五步驟  提出問題 (Question formulation)  搜尋證據 (Evidence search)  嚴格判讀 (Critical appraisal)  恰當運用 (Evidence application)  評估結果 (Outcome evaluation)

3. 問題  住院醫師林玲玲對主治醫師的醫囑有所 疑問，於是努力搜尋文獻， 終於找到幾 篇論文，但是其中結論各有不同，而且 也的文章感覺好像不太可信，又有的不 太適用，因為沒有人教過她如何嚴謹地 評讀論文，所以她實在不知道該怎麼辦。

4. 答案？  看是哪一本期刊？  看屬哪一個國家？  看從哪一個醫院？  看自哪一個作者？  還要看什麼？

5. 嚴格判讀 (Critical appraisal)  信度 (reliability)  效度 (validity)  重要性 (importance)  實際運用之可能 (applicability)

6. Level of Evidence (Oxford CEBM) LevelTherapy/Prevention, Aetiology/Harm 1a SR (with homogeneity*) of RCTs 1b Individual RCT (with narrow Confidence Interval ‡ ) 1c All or none§ 2a SR (with homogeneity*) of cohort studies 2b Individual cohort study (including low quality RCT; e.g., <80% follow-up) 2c "Outcomes" Research; Ecological studies 3a SR (with homogeneity*) of case-control studies 3b Individual Case-Control Study 4 Case-series (and poor quality cohort and case- control studies§§) 5 Expert opinion without explicit critical appraisal, or based on physiology, bench research or "first principles" Produced by Bob Phillips, Chris Ball, Dave Sackett, Doug Badenoch, Sharon Straus, Brian Haynes, Martin Dawes since November 1998.

8. Varieties of RCT in Surgery  Surgery A vs. Surgery B  Surgical vs. Medical  Surgery vs. Observation  Early vs. Delayed Surgery  Surgery vs. Surgery + X  Procedure A vs. Procedure B of Surgery  Medicine A vs. Medicine B in Surgery

9. http://www.cebm.net/index.aspx?o=1157

12. http://www.phru.nhs.uk/Pages/PHD/resources.htm

13. 2. Exposure Gp 3. Comparison 5. Time 4.Outcomes + - 1. Participants GATE Frame: 5 PECOT components GATE a general appraisal tool for epidemiology http://www.health.auckland.ac.nz/comhealth/epiq/epiq.htm

15. 10 questions to help you make sense of randomised controlled trials The 10 questions are adapted from Guyatt GH, Sackett DL, and Cook DJ, Users’ guides to the medical literature. II. How to use an article about therapy or prevention. JAMA 1993; 270 (21): 2598-2601 and JAMA 1994; 271(1): 59-63 © Public Health Resource Unit, England (2006). All rights reserved.

16. A. Are the results of the study valid? Screening questions 1. Did the study ask a clearly-focused question?  Consider if the question is “focused” in terms of :  the population  the intervention  the outcomes

17. 2. Was this a randomised controlled trial (RCT)?  Consider:  why this study was carried out as an RCT  if this was the right research approach for the question being asked Is it worth continuing?

18. Detailed questions 3. Were participants appropriately allocated to intervention and control groups?  Consider:  how participants were allocated to intervention and control groups. Was the process truly random?  whether the method of allocation was described. Stratification, blocked etc?  how the randomisation schedule was generated and how a participant was allocated to a study group  if the groups were well balanced.  if there were differences reported that might have explained any outcome(s) (confounding)

19. 4. Were participants, staff and study personnel ‘blind’ to participants’ study group?  Consider:  the fact that blinding is not always possible  if every effort was made to achieve blinding  if you think if matters in this study  the fact that we are looking for ‘observer bias’

20. 5. Were all of the participants who entered the trial accounted for at its conclusion?  Consider:  if any intervention-group participants got a control- group option or vice versa (cross-over?)  if all participants were followed up in each study group (was there loss-to-follow-up?)  if all the participants’ outcomes were analysed by the groups to which they were originally allocated (intention-to-treat analysis)  what additional information would you liked to have seen to make you feel better about this

21. 6. Were the participants in all groups followed up and data collected in the same way?  Consider:  if, for example, they were reviewed at the same time intervals and if they received the same amount of attention from researchers and health workers. Any differences may introduce performance bias.

22. 7. Did the study have enough participants to minimise the play of chance?  Consider:  if there is a power calculation. This will estimate how many participants are needed to be reasonably sure of finding something important (if it really exists and for a given level of uncertainty about the final result).

23. B. What are the results? 8. How are the results presented and what is the main result?  Consider:  if, for example, the results are presented as a proportion of people experiencing an outcome, such as risks, or as a measurement, such as mean or median differences, or as survival curves and hazards  how large this size of result is and how meaningful it is  how you would sum up the bottom-line result of the trial in one sentence

24. 9. How precise are these results?  Consider:  if the result is precise enough to make a decision  if a confidence interval were reported. Would your decision about whether or not to use this intervention be the same at the upper confidence limit as at the lower confidence limit?  if a p-value is reported where confidence intervals are unavailable

25. C. Will the results help locally? 10. Were all important outcomes considered so the results can be applied?  Consider whether :  the people included in the trial could be different from your population in ways that would produce different results  your local setting differs much from that of the trial  you can provide the same treatment in your setting

26.  Consider outcomes from the point of view of the:  individual  policy maker and professionals  family/carers  wider community  Consider whether:  any benefit reported outweighs any harm and/or cost. If this information is not reported can it be filled from elsewhere?  policy or practice should change as a result of the evidence contained in this trial