EBM demonstration

EBM demonstration

小港醫院神經科 藍聖星主治醫師

實證醫學的步驟

1. 提出一個好的問題– 可以被回答的問題

2. 搜尋資料庫3. 嚴謹的研判所找到的證據4. 整合到臨床所遇到的問題上面，給

出答案5. 稽核

Clinical Problem

• 給中風病人使用抗凝血劑，對未來會不會比較好

PICO

• Patient: 目標是哪些病人？• Intervention: 使用了哪一種治療方法？• Comparison: 要跟什麼比？• Outcome: 要比什麼？

容易解答的問題

• Patient– Stroke patients

• Intervention– Anti-coagulation

That will go WRONG !

• Comparison ( 跟什麼比？ )– Standard treatment: Anti-platelet– Unclear: Placebo

• Outcome ( 比什麼？ )– Morbidity vs Mortality– Long term prognosis

• Recurrent rate ?• ADF ?• Complication rate ?• Co-morbidity ?• ……….

比較容易回答的題目

• 對於中風後的病患來說，使用抗凝血劑的治療，比起使用抗血小板藥物的治療，是否在中風的復發率會有不同的影響

Show Me the PICO !!

• Patient: Stroke

• Intervention: Anti-coagulation

• Comparison: Anti-Platelet

• Outcome: Recurrent rate

實證醫學的步驟

1. 提出一個好的問題2. 搜尋資料庫

• Guideline• EBM Reviews• Pubmed

3. 嚴謹的研判所找到的證據4. 整合到臨床所遇到的問題上面，給出答

案5. 稽核

Databases…………Orz…

…that may go WRONG !!

• Search priority

• Key words– Broaden? Narrow?

• Expressions

Key Words

• Shift the WORDs– Aspirin <> Antiplatelet– Coumadin <> Anticoagulation– Stroke <> CVA

• DO NOT Use shortcuts

Guideline

National Clearing House

• www.GUIDELINE.gov• www.NGC.org

• Always search for published guidelines• A guideline is any document that aims to

streamline particular processes according to a set routine

Guideline

Guideline

• 33 hits

• 5 Selected

EBM Reviews

• Cochrane Review Groups

• ACP Journal Club

• UpToDate

• POEMS

• …

ACP Journal Club

ACP Journal Club

ACP Journal CLUB

ACP Journal Club

ACP Journal CLub

• 12 hits,

• 4 selected

Cochrane Review Group

Cochrane Library

Cochrane Library

Cochrane Review Group

• 33 hits

• 5 selected

實證醫學的步驟

1. 提出一個好的問題2. 搜尋資料庫3. 嚴謹的研判所找到的證據

• 這個結果的 Level of Evidence• NNT & NNH (Number Needs to Treat)

4. 整合到臨床所遇到的問題上面，給出答案

5. 稽核

Conclusions

• Long-term anticoagulation may be more effective than antiplatelet treatment for preventing nonfatal stroke but not other vascular events in patients with nonrheumatic AF.

• In patients with acute ischemic stroke, anticoagulants used alone or with antiplatelet agents are not superior to antiplatelet agents used alone.

• There is no evidence that stroke patients with a normal heart rhythm benefit from anticoagulants.

Abstracts: Cochrane Review• In most ischaemic strokes, the blockage is caused by a blo

od clot. Anticoagulant drugs, such as warfarin, may prevent such clots forming and hence could prevent stroke. However, anticoagulant drugs may also cause bleeding in the brain and this complication could offset any benefits. This review identified a number of trials, in patients who had had a stroke, of anticoagulants to prevent further strokes. There was good evidence that anticoagulants could cause serious bleeding, and there was no evidence that anticoagulants were of benefit. However, other trials show that patients with an irregular heartbeat (atrial fibrillation) and a recent stroke due to a blocked artery do benefit from anticoagulants. New trials are underway to see whether stroke patients with a normal heart rhythm can get greater benefit from anticoagulants than from standard clot-preventing treatments such as aspirin and other antiplatelet drugs.

P Sandercock, O Mielke, M Liu, C Counsell; Anticoagulants for preventing recurrence following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack. 2003

Clinical Applications

• Prevention of Noncardioembolic Cerebral Ischemic Events: Oral Anticoagulants– For most patients with noncardioembolic strok

e or TIA, the guideline developers recommend antiplatelet agents over oral anticoagulation (Grade 1A).

– For patients with well-documented prothrombotic disorders, the guideline developers suggest oral anticoagulation over antiplatelet agents (Grade 2C).

Clinical Applications

• Patients with Stroke with Underlying Atrial Fibrillation: Antiplatelet Agents– For patients with cardioembolic stroke

who have contraindications to anticoagulant therapy, the guideline developers recommend aspirin (Grade 1A).

Clinical Applications

• Patients with Aortic Atheromata– In patients with stroke associated with aortic a

therosclerotic lesions, the guideline developers recommend antiplatelet therapy over no therapy (Grade 1C+). For patients with cryptogenic stroke associated with mobile aortic arch thrombi, the guideline developers suggest either oral anticoagulation or antiplatelet agents (Grade 2C).

Clinical Applications

• Patients with Patent Foramen Ovale (PFO)– In patients with cryptogenic ischemic st

roke and a patent foramen ovale, the guideline developers recommend antiplatelet therapy over no therapy (Grade 1C+), and suggest antiplatelet agents over anticoagulation (Grade 2A).

Clinical Applications

• Mitral Valve Strands and Prolapse– In patients with mitral valve strands or

prolapse, who have a history of TIA or stroke, the guideline developers recommend antiplatelet therapy (Grade 1C+).

Key Point

• Guideline or System Reviews are favoured– Clinical Application– Conclusion

• Critically appraisal for the result of Pubmed Search – Guideline and SRs are NOT AVAILABL

E

APP: Pubmed Search

APP: Pubmed Search

實證醫學的步驟

1. 提出一個好的問題2. 搜尋資料庫3. 嚴謹的研判所找到的證據4. 整合到臨床所遇到的問題上面，給

出答案• 問題問的不對？• 這個答案是不是你要的？

5. 稽核

The Patient Profile

• Does he meet the following criterias?

• Prothrombic conditions• Atrial fibrillations• Aortic Atheromata, and the stroke wa

s highly suspected to relate with