Transcript PPT
神經內科 王志弘 + 治療或處置的危害 + 環境的危害 + Systemic review of randomized trials – 單獨一個研究，常常無法顯示出一些少見的不 良反應 + Cohort study + Case control studies + Cross-sectional studies Included Subjects Randomised to aspirin or placebo aspirin placebo Myocardial infarction yes no 5 years Randomized Controlled Trial Longitudinal study 4 Included Subjects smoking status measured smokers Lung cancer non-smokers yes no + Cohort study + Longitudinal study 5 years 5 Included Subjects smoking status measured smokers Lung cancer non-smokers yes no + Case Control Study + Longitudinal study 10 years 6 Included Subjects smoking status measured smokers Lung function non-smokers normal abnormal + Cross-sectional study 7 Are the results of this harm/etiology study valid? + 控制組 + 客觀、或盲化（blind） – 治療、暴露、結果 + 追蹤： – 時間：是否夠長 – 完整性：lost to follow up （<20%） + 因果相關 Case Control RCT or cohort + Confounding factor: exposed and non- exposed not randomized + Prospective vs retrospective Retrospective cohort Administrative databases 健保資料庫 + the outcome of interest is rare or takes a long time to develop – 腫瘤、矽肺病 – 只能使用 case control study + 有些 confounder 無法測量 – Transient – To severe leading to death + The selection of control + Statistical significance, if large number of association factors + Exposure and outcome are measured at the same time + case reports of one patient (or a case series of a few patients) – Thalidomide and 海豹肢症 + highlight the need for other studies + Blind, objective + Administrative database – 健保資料庫，病歷紀錄 + Patient or doctor recall + 統計相關不等於因果相關 + Diagnostic tests for causation – the exposure preceded the onset of the outcome – a dose–response gradient? – dechallenge–rechallenge – the association consistent from study to study + Does the association make biological sense? Are the valid results of this harm study important? Magnitude, precision Case Control RCT or cohort RCT or cohort + 20 980 2 998 Case Control + 90 45 10 55 + risks = odds/(1 + odds) + odds = (risk/1 – risk) + ORs and RRs >1：接觸者得病的機會增加 + ORs and RRs <1：接觸者得病的機會減少 + 通常 – case control study, OR >4, 認為有意義 – Cohort study, RR>3 就認為有意義 – 還要考慮結果（outcome）的嚴重程度 + http://ktclearinghouse.ca/cebm/toolbox/ortonnt + Confidence Interval + the adjusted OR for ischemic heart disease or stroke associated with a 25% lower serum homocysteine level was 0.89 with 95% CI 0.83–0.96. + In our caffeine study, the OR was 2.4 (adjusted for age and smoking) with 95% CI 1.1–6.5. Can this valid and important evidence about harm be applied to our patient? 研究方法? RCT, cohort, case control, cross-sectional