總結證據結果
&
Meta-Analysis
101-7-3
 Lecture
(7-3)
 Meta-analysis
室
上機操作 (7-17):電腦教
Summary of the relevant references
Meta-Analysis

Why meta-analysis

Heterogeneity of the studies

Fixed effect methods for combining study estimate

Random effect methods for combining study estimate

Sensitivity analysis

Presenting the results of a meta-analysis
Meta-analysis
 積少成多
 減少
(n大是王道)
sampling errors
 Homogenicity
檢測
 一致:IPD
(individual patient data), summary
data結果一致
 存在
heterogenicity: summary data (metaanalysis)
Meta-analysis
 Weight=
1/variance
 在meta-analysis中,
study的 重要性 (
貢獻性)依 weight衡量.
study
n
d
s
Var (d)
95% CI
1
17/20
0.28
10.59
0.11
-0.37 to 0.93
2
39/40
-0.81
16.18
0.05
-1.27 to -0.35
3
15/15
-0.9
8.86
0.15
-1.65 to -0.15
126/139
-0.85
12.49
0.02
-1.1 to -0.59
.
.
.
.
.
9
.
Due to heterogenicity, we do Meta-Analysis
 Heterogenicity
 Chi-square
test:
test: p<0.05 異質性過高 個別分析,評估
異質性來源
 Chi-square
test: p>0.05 進入 meta-analysis
 異質程度: I2=(Q-df)/Q
x 100%
(df=study numbmer -1)
low: <=0.2; middle: 0.2-0.5; high: >0.5
 但書:
 10篇studies以下,改
用 0.1當 cutpoint
 P-value
 >=0.5

for heterogenicity
Fixed-effect model
0.05-0.5 Random-effect model
 <0.05
評估異質性來源
 Fixed-effect
model: the between groups
variance is ignored; only with-in study
variance is considered
 Random-effect
model: consider both the
between- and with-study variation; 較保守
策略
weight of study: 在random-effect
model中, 小型study權重相對提高.
 Relative
Example
Forest plot
<0.05評估異質性
來源
P=0.065 random
effect
Subgroup analysis
Male
Female
Publication bias: Funnel plot
Egger’s test
Egger et al. (1997) proposed a test for asymmetry of the funnel
plot. This is a test for the Y intercept = 0 from a linear regression
of normalized effect estimate (estimate divided by its standard
error) against precision (reciprocal of the standard error of the
estimate). StatsDirect provides this bias indicator method with all
meta-analyses. Please note that the power of this method to
detect bias will be low with small numbers of studies.
 檢測 intercept是否為”0”
Sensitivity analysis
 Sensitivity
of results of inclusion of criteria:
 delete some study
 Sensitivity
of results to meta-analysis
methods (different weighting)

Weighting method
Log scale
其他8個studies
9 個 studies
Sensitivity test
Summary

Abstract

Background

Hypothesis

Review methods

Details of studies included

Details of studies excluded

Results of the review

Analysis of the robustness of the results: sensitivity test

Discussion: included publication bias
Box4.1 將取自納入系統性回顧之研究的資訊製表(1/2)
Box4.1 將取自納入系統性回顧之研究的資訊製表(2/2)
Box C3.5 有關抗菌製劑治療慢性傷口之回顧所納入研究之
發現簡要總結(1/2)
Box C3.5 有關抗菌製劑治療慢性傷口之回顧所納入研究之
發現簡要總結(2/2)
Box4.2 估計納入系統性回顧之個別研究觀察到之效果(1/3)
Box4.2 估計納入系統性回顧之個別研究觀察到之效果(2/3)
Box4.2 估計納入系統性回顧之個別研究觀察到之效果(3/3)
Box4.3 總結納入系統性回顧之研究中觀察到的效果(1/2)
Box4.3 總結納入系統性回顧之研究中觀察到的效果(2/2)
Box4.4 用統合分析彙總(1/2)
Box4.4 用統合分析彙總(2/2)
Box4.5 探索臨床異質性(1/2)
Box4.5 探索臨床異質性(2/2)
解讀文獻回顧發現
101-7-3
Box5.1 用以探索有無出版及相關偏差的漏斗圖
Box5.2 用研究設計評估推論的強度(1/2)
Box5.2 用研究設計評估推論的強度(2/2)
Box5.3 使用研究品質來評估推論的強度(1/3)
Box5.3 使用研究品質來評估推論的強度(2/3)
Box5.3 使用研究品質來評估推論的強度(3/3)
Box5.4 為根據結果回顧的發現作出之醫療建議分等級(1/2)
Box5.4 為根據結果回顧的發現作出之醫療建議分等級(2/2)
Box5.5 將來自回顧的彙總效果因時地制宜施於臨床情境 (1/2)
Box5.5 將來自回顧的彙總效果因時地制宜施於臨床情境 (2/2)