Clinical Scenario

Step 1: Ask an answerable clinical question--P. I. C. O. Patient / Problem : Intervention / Exposure: Comparison: Outcome:

PICO Question: Patient / Problem : Intervention / Exposure: Comparison: Outcome:

Step 2: Effective searches for the best Evidence

搜尋策略的設計表 SEARCH STRATEGY DESIGN TABLE 主要詞彙 Primary Term 同義字 Synonym 1 同義字 Synonym 2 P OR AND I C O

實際搜尋 ACTUAL SEARCHES Cochrane 搜尋　　　　　　　　　　　 文獻數　　　　　　　　　　　　 PubMed 搜尋

Step 3: Critically appraise that evidence for its validity and importance

A.文獻的結果能令人信服嗎? Are the results of this prognosis study valid?

1. Was a defined, representative sample of patients assembled at a common (usually early) point in the course of their disease? 本文獻： □Yes □No □Unclear 評論Comment：

2. Was patient follow-up sufficiently long and complete? 本文獻： □Yes □No □Unclear 評論Comment：

3. Were objective outcome criteria applied in a “blind” fashion? 本文獻： □Yes □No □Unclear 評論Comment：

4. If subgroups with different prognoses are identified, was there adjustment for important prognostic factors? 本文獻： □Yes □No □Unclear 評論Comment：

5. Was there validation in an independent group (“test set”) of patients?   本文獻： □Yes □No □Unclear 評論Comment：

B.文獻的結果夠重要嗎? Are the valid results of this prognosis study important?

6. How likely are the outcomes over time? Typically, results from prognosis studies are reported in one of three ways: as a percentage of survival at a particular point in time (such as 1-year or 5-year survival rates); 2) as median survival (the length of follow-up by which 50% of study patients have died); or 3) as survival curves that depict, at each point in time, the proportion (expressed as a percentage) of the original study sample who have NOT yet had a specified outcome. In prognosis studies we often find results presented as Kaplan–Meier curves, which are a type of survival curve. Prognosis shown as survival curves (dashed line indicates median survival). A: Good prognosis (or too short a study!). B: Poor prognosis early, then slower increase in mortality, with median survival of 3 months. C: Good prognosis early, then worsening, with median survival of 9 months. D: Steady prognosis.

7. How precise are the prognostic estimates?

C.文獻的結果能應用到我們的病人嗎? Can we apply this valid, important evidence about prognosis in caring for our patient?

8. Were the study patients similar to our own?

9. Will this evidence make a clinically important impact on our conclusions about what to offer or tell our patient?