110 likes | 477 Views
實施實證醫學五大步驟. step 1. 整理出一個可以回答的問題 step 2. 尋找文獻證據 step 3. 嚴格評讀文獻 ( Critical appraisal ) step 4. 應用於病人身上 step 5. 對過程進行稽核. What is CAT?. Systematic evaluation of study/studies To critically appraise -- not only “ read ” , but also “ assess ”
E N D
實施實證醫學五大步驟 step 1.整理出一個可以回答的問題 step 2. 尋找文獻證據 step 3. 嚴格評讀文獻 (Critical appraisal ) step 4. 應用於病人身上 step 5. 對過程進行稽核
What is CAT? • Systematic evaluation of study/studies • To critically appraise -- not only “read”, but also “assess” • Simplify appraisal with VIP (or PICO/RAMbo)
CRITICAL APPRAISAL SKILLSWhat is VIP? Validity (Reliability) 效度/信度 Can we believe it ? (研究方法的探討) Importance (Impact) 重要性 We believe it ! But does it matter? (研究結果的分析) Practice (Applicability) 臨床適用性 If we believe it - does it apply to our patients? (如何在臨床運用)
Validity (Reliability)What is RAMbo? “Do we believe it? ” • Randomized:Was it randomised? Were the groups similar? • Accounted for all patients • Measurement: blinded or objective
“該治療性研究結果是可信的嗎?” EVIDENCE-BASED MEDICINE How to Practice and Teach EBM • 病人的治療分派是否為隨機?隨機方式是否恰當?實驗開始前,實驗組及對照組是否相似、可比較?(R) • 病人追蹤是否夠久、夠完整?所有病人是否依其原先分派組別作分析?(A) • 病人及醫師是否對治療不知情(blind)?實驗組及對照組是否被同等對待?(M)
Importance (Impact) “ We believe it !But-does it matter? ” • What were the results? -How large was the treatment effect? -How precise was the estimate of the treatment effect?
In therapy study • Number needed to treat (NNT) • Relative risk (RR) • Relative risk reduction (RRR) • Absolute risk reduction (ARR)
1. 實驗組的發病率(experimental event rate,EER):即在施與實驗組療法的病患,發生研究所關心之結果的比率。 • 2. 對照組的發病率(control event rate,CER):即在研究中未施與實驗組的療法,產生研究所關心之結果的比率。 • 3. 絕對危險降低度(absolute risk reduction,ARR)=CER-EER。 • 4. 使一位病人達到治療組治療之有益結果所需治療的病患數(number needed to treat,NNT)=1/ARR。 • 5. 絕對危險增加度(absolute risk increase,ARI)= EER-CER。 • 6. 增加一位受試者罹患某種醫源性傷害的治療病人數(number needed to harm,NNH)=1/ARI。 • 7. 信賴區間(confidence interval,CI):指在某一信賴程度內,由樣本統計量所求出預期可以包括母群體的範圍。
將12,562位有不穩定型心絞痛的患者分兩組進行隨機對照試驗,分別接受aspirin或合併使用clopidogrel ,九個月後研究結果:單獨使用aspirin(對照組)其心肌梗塞、中風或心臟血管疾病死亡率為11.47%;合併使用aspirin及clopidogrel (實驗組)其心肌梗塞、中風或心臟血管疾病死亡率為9.28%。對照組發生非致死性出血副作用為2.7% ;實驗組為3.6% 。 CER=11.47%; EER=9.28% RR=9.28%/11.47%=0.81 RRR=(11.47%-9.28%)/11.47%=19% ARR=11.47%-9.28%=2.19% NNT=1/2.19%=46 ARI(絕對危險性增加率)=3.6%-2.7%=0.9% NNH=1/0.9%=111