CASP, an evidence based approach in health and social care, and its checklists

1. 張哲浣報告 CASP, an evidence based approach in health and social care, and its checklists

2. CASP, an evidence based approach in health and social care • 整個CASP是一種包含EBM的方案 • 特色是在評讀方面 • CASP 目標(for health and social care) ≧ an EBM program; 但策略類似,特色使用的checklists • Ps:是否可做為寫作的checklists?

4. 何謂 CASP • CASP 為 Critical Appraisal Skills Programme 之縮寫. Critical appraisal is the process of carefully and systematically examiningresearch to judgeits trustworthiness (可信賴), and its value (價值) and relevance (關聯) in a particular context. • 目的:了解證據(Make sense of evidence).

5. CASP標準動作 • Find • Appraise (檢驗判斷) • Act (做)

6. CASP 起源 • CASP是由英國健保(ＮＨＳ)的公共衛生資源部門所發展的文獻評讀工具，其中critical appraisal tools針對各種不同研究設計提供不同的評讀表單資源 • The Critical Appraisal Skills Programme (CASP) was developed in Oxford in 1993 and has since helped to develop an evidence based approach in health and social care, working with local, national and international partner organisations.

7. workshops and resources • CASPs workshops and resources aim to help participants put knowledge into practice by learning how to • systematically formulate questions, • find research evidence, • appraise research evidence and • act on (照著...做) what they find.

8. CASP─ Find, Appraise, Act • The Critical Appraisal Skills Programme helps people acquire skills in making sense of scientific evidence about health care. • This is because in order to make use of the best available evidence from scientific research, we need to be able to :

9. The CASP International Network (CASPin) • A non-profit making organisation for people promoting skills in finding, critically appraising and acting on research evidence. CASPin has been an informal network since 1998, and members have developed similar critical appraisal skills programmes in Spain (CASPe), Hungary, Poland, Romania, Japan, Norway and India. Many individuals have organised CASP workshops in about 30 other countries, settings and audiences, particularly South America, and Central and Eastern Europe.

11. The Creative Commons License • A set of eight critical appraisal tools to use when reading research, these include tools for Systematic Reviews. Randomised Controlled Trials, Cohort Studies, Case Control Studies, Economic Evaluations, Diagnostic Studies, Qualitative Studies and Clinical Prediction Rule. These are free to download and can be used by anyone under the Creative Commons License.

12. CASP八種checklists (討論前四項) • CASP Randomised Controlled Trial • CASP Systematic Review • CASP Cohort Study • CASP Case Control Study • CASP Qualitative Research • CASP Economic Evaluations • CASP Diagnostic Test • CASP Clinical Prediction Rule

13. Clinical trial-classifying clinical trials is by the way the researchers behave • In an observational study, the investigators observe the subjects and measure their outcomes. The researchers do not actively manage the study in both the treatment and the assignment of subjects. • In an interventional study, the investigators give the research subjects a particular medicine or other intervention. Usually, they compare the treated subjects to subjects who receive no treatment or standard treatment. Then the researchers measure how the subjects' health changes.

14. Observational study vs Experiment (randomized controlled trial) • An observational study draws inferences about the possible effect of a treatment on subjects, where the assignment of subjects into a treated group versus a control group is outside the control of the investigator. • This is in contrast with experiments, such as randomized controlled trials, where each subject is randomly assigned to a treated group or a control group.

15. Clinical trials─classifiedby their purpose • Prevention trials • Screening trials • Diagnostic trials • Treatment trials • Quality of life trials (supportive care trials) • Compassionate use trials or expanded access trials

17. Checklists • 10-12 questions to help you make sense of the studies. • Critical appraisal幫助Systemic review之第四第五步驟:綜合分析及解讀

18. Three broad issues • Are the results of the trial valid? (Section A) • What are the results? (Section B) • Will the results help locally? (Section C)

19. Screenging and detailed questions • Screening─有關study design方面的問題 2-3題; 之後會有圖示 • "Is it worth continuing?" Or • 若study design尚可接受,才進入detailed critical appraisal.

20. A. Case control study

21. (A) Are the results of the study valid? 1-6題

22. 1. Did the study address a clearly focused issue?Yes  Can’t tell  No • HINT: A question can be focused in terms of • • The population studied • • The risk factors studied • • Whether the study tried to detect a beneficial or harmful effect?

23. 2. Did the authors use an appropriate method to answer their question? Yes  Can’t tell  No • HINT: Consider • • Is a case control study an appropriate way of Answering the question under the circumstances? (Is the outcome rare or harmful) • • Did it address the study question?

24. Is it worth continuing? or

25. 3. Were the cases recruited in an acceptable way?  Yes  Can’t tell  No HINT: We are looking for selection bias which might compromise validity of the findings • Are the cases defined precisely? • Were the cases representative of a defined population? (geographically and/or temporally?) • Was there an established reliable system for selecting all the cases • Are they incident or prevalent? • Is there something special about the cases? • Is the time frame of the study relevant to disease/exposure? • Was there a sufficient number of cases selected? • Was there a power calculation?

26. 「顯著性」、「統計檢定力」、「效果量」與「樣本數」此4者之間的關係是互補的，當我們確定其中3個項目時，就能決定第4個。「顯著性」、「統計檢定力」、「效果量」與「樣本數」此4者之間的關係是互補的，當我們確定其中3個項目時，就能決定第4個。

27. 4. Were the controls selected in an acceptable way?  Yes  Can’t tell  No HINT: We are looking for selection bias which might compromise The generalisibilty of the findings • Were the controls representative of defined population (geographically and/or temporally) • Was there something special about the controls? • Was the non-response high? Could non-respondents be different in any way? • Are they matched, population based or randomly selected? • Was there a sufficient number of controls selected?

28. 5. Was the exposure accurately measured to minimise bias?  Yes  Can’t tell  No HINT: We are looking for measurement, recall or classification bias • Was the exposure clearly defined and accurately measured? • Did the authors use subjective or objective measurements? • Do the measures truly reflect what they are supposed to measure? (Have they been validated?) • Were the measurement methods similar in the cases and controls? • Did the study incorporate blinding where feasible? • Is the temporal relation correct? (Does the exposure of interest precede the outcome?)

29. 6. (a) What confounding factors have the authors accounted for?List: • HINT: List the ones you think might be important, that The author missed. • • Genetic • • Environmental • • Socio-economic

30. 6. (b) Have the authors taken account of the potential confounding factors in the design and/or in their analysis?  Yes  Can’t tell  No • HINT: Look for • • Restriction in design, and techniques e.g. modelling stratified-, regression-, or sensitivity analysis to correct, control or adjust for confounding factors

31. (B) What are the results? 7-9題

32. 7. What are the results of this study? HINT: Consider • What are the bottom line results? • Is the analysis appropriate to the design? • How strong is the association between exposure and outcome (look at the odds ratio)? • Are the results adjusted for confounding, and might confounding still explain the association? • Has adjustment made a big difference to the OR?

33. 8. How precise are the results?How precise is the estimate of risk? • HINT: Consider • • Size of the P-value • • Size of the confidence intervals • • Have the authors considered all the important variables? • • How was the effect of subjects refusing to participate evaluated?

34. 9. Do you believe the results? Yes  Can’t tell  No • HINT: Consider • • Big effect is hard to ignore! • • Can it be due to chance, bias or confounding? • • Are the design and methods of this study sufficiently flawed to make the results unreliable? • • Consider Bradford Hills criteria for causality (e.g. time sequence, dose-response gradient, strength, biological plausibility)

35. (C) Will the results help locally? 10-11題

36. 10. Can the results be applied to the local population?  Yes  Can’t tell  No • HINT: Consider whether • • The subjects covered in the study could be sufficiently different from your population to cause concern • • Your local setting is likely to differ much from that of the study • • Can you quantify the local benefits and harms?

37. 11. Do the results of this study fit with other available evidence? Yes  Can’t tell  No • HINT: Consider all the available evidence from RCT’s, systematic reviews, cohort studies and case-control studies as well for consistency.

38. Remember One observational study rarely provides sufficiently robust evidence to recommend changes to clinical practice or within health policy decision making. However, for certain questions observational studies provide the only evidence. Recommendations from observational studies are always stronger when supported by other evidence.

39. B. RCT

40. (A) Are the results of the study valid? 1-6題

41. 1. Did the trial address a clearly focused issue?  Yes  Can’t tell  No • HINT: An issue can be ‘focused’ In terms of •  The population studied •  The intervention given •  The comparator given •  The outcomes considered

42. 2. Was the assignment of patients to treatments randomised? Yes  Can’t tell  No • HINT: Consider •  How was this carried out? •  Was the allocation sequence concealed from researchers and patients?

43. 3. Were all of the patients who entered the trial properly accounted for at its Conclusion? Yes  Can’t tell  No • HINT: Consider •  Was the trial stopped early? •  Were patients analysed in the groups to which they were randomised?

44. Is it worth continuing? or

45. 4. Were patients, health workers and study personnel ‘blind’ to treatment? Yes  Can’t tell  No • HINT: Think about •  Patients? •  Health workers? •  Study personnel?

46. 5. Were the groups similar at the start of the trial?  Yes  Can’t tell  No • HINT: Look at •  Other factors that might affect the outcome such as age, sex, social class

47. 6. Aside from the experimental intervention, were the groups treated equally? Yes  Can’t tell  No

48. (B) What are the results? 7-8題

49. 7. How large was the treatment effect? • HINT: Consider •  What outcomes were measured? •  Is the primary outcome clearly specified? •  What results were found for each outcome?

50. 8. How precise was the estimate of the treatment effect? • HINT: Consider •  What are the confidence limits?