| | | |
% Bias
|
% Coverage
|
% Statistical Power
|
I
2(%)
|
|---|
| | | |
τ = 0s
|
τ = 0.5s
|
τ = 0s
|
τ = 0.5s
|
τ = 0s
|
τ 0.5s
|
τ 0.5s
|
|---|
|
Δ
|
n (exp/contr)
|
k
|
MD
|
SMD
|
RoM
|
MD
|
SMD
|
RoM
|
MD
|
SMD
|
RoM
|
MD
|
SMD
|
RoM
|
MD
|
SMD
|
RoM
|
MD
|
SMD
|
RoM
|
MD
|
SMD
|
RoM
|
|---|
|
SMD = 0.2
|
14/6
|
5
|
-1
|
-5
|
0
|
0
|
-5
|
0
|
94
|
97
|
94
|
90
|
92
|
90
|
15
|
10
|
11
|
14
|
12
|
12
|
59
|
44
|
54
|
| | |
10
|
1
|
-4
|
-1
|
2
|
-4
|
-1
|
94
|
97
|
93
|
92
|
93
|
91
|
25
|
18
|
18
|
18
|
16
|
14
|
60
|
44
|
55
|
| | |
30
|
0
|
-5
|
-1
|
1
|
-6
|
-1
|
94
|
97
|
91
|
93
|
94
|
93
|
59
|
53
|
44
|
36
|
35
|
27
|
60
|
44
|
55
|
|
MD = 8
|
134/66
|
5
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
97
|
97
|
88
|
88
|
88
|
78
|
77
|
76
|
21
|
21
|
21
|
92
|
91
|
91
|
|
RoM = 1.08
| |
10
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
96
|
96
|
92
|
91
|
91
|
98
|
98
|
97
|
27
|
27
|
27
|
92
|
91
|
91
|
| | |
30
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
96
|
96
|
94
|
94
|
94
|
100
|
100
|
100
|
56
|
57
|
57
|
92
|
91
|
91
|
|
SMD = 0.5
|
14/6
|
5
|
0
|
-4
|
-1
|
0
|
-5
|
0
|
94
|
97
|
94
|
90
|
92
|
90
|
57
|
50
|
50
|
41
|
37
|
36
|
59
|
44
|
54
|
| | |
10
|
0
|
-5
|
-1
|
1
|
-5
|
-1
|
94
|
97
|
93
|
92
|
93
|
91
|
86
|
83
|
79
|
62
|
61
|
56
|
60
|
44
|
55
|
| | |
30
|
0
|
-5
|
-1
|
0
|
-6
|
-1
|
94
|
96
|
91
|
93
|
93
|
92
|
100
|
100
|
100
|
96
|
97
|
94
|
60
|
43
|
56
|
|
MD = 20
|
134/66
|
5
|
0
|
0
|
0
|
0
|
-1
|
1
|
96
|
96
|
97
|
88
|
88
|
88
|
100
|
100
|
100
|
60
|
61
|
60
|
92
|
91
|
91
|
|
RoM = 1.2
| |
10
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
96
|
96
|
92
|
92
|
91
|
100
|
100
|
100
|
85
|
86
|
85
|
92
|
91
|
91
|
| | |
30
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
96
|
95
|
94
|
94
|
94
|
100
|
100
|
100
|
100
|
100
|
100
|
92
|
91
|
91
|
|
SMD = 0.8
|
14/6
|
5
|
0
|
-4
|
-1
|
0
|
-5
|
0
|
94
|
97
|
93
|
90
|
92
|
90
|
91
|
89
|
87
|
71
|
69
|
66
|
59
|
43
|
54
|
| | |
10
|
0
|
-5
|
-1
|
0
|
-5
|
-1
|
94
|
96
|
92
|
92
|
93
|
91
|
100
|
100
|
99
|
93
|
93
|
91
|
60
|
43
|
55
|
| | |
30
|
0
|
-5
|
-2
|
0
|
-6
|
-1
|
94
|
94
|
90
|
93
|
92
|
92
|
100
|
100
|
100
|
100
|
100
|
100
|
60
|
42
|
56
|
|
MD = 32
|
134/66
|
5
|
0
|
0
|
0
|
0
|
-1
|
1
|
96
|
96
|
96
|
88
|
88
|
88
|
100
|
100
|
100
|
91
|
91
|
91
|
92
|
91
|
91
|
|
RoM = 1.32
| |
10
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
96
|
96
|
92
|
92
|
91
|
100
|
100
|
100
|
100
|
100
|
100
|
92
|
91
|
91
|
| | |
30
|
0
|
0
|
0
|
0
|
-1
|
0
|
96
|
96
|
95
|
94
|
94
|
93
|
100
|
100
|
100
|
100
|
100
|
100
|
92
|
91
|
91
|
- Results of 10,000 simulations per scenario with a standard deviation equal to 40% of the control mean, for each combination of effect size (0.2, 0.5, and 0.8 standard deviation units), number of patients (14/6 and 134/66 experimental/control patients per trial), and number of trials (5, 10, and 30). The "% Bias" columns show the bias of each effect measure (MD, SMD, RoM) expressed as percentages of the expected values (negative sign denotes less than expected value), with and without heterogeneity. The "% coverage" columns show the percentage of cases that the true value falls within the 95% confidence interval of the simulated result, with and without heterogeneity. The "% statistical power" columns show the percentage of cases that the 95% confidence interval of the simulated result yields a significant treatment effect (i.e. excluding zero for MD and SMD, and one for RoM), with and without heterogeneity. The I
2 column shows the degree of heterogeneity only for the scenarios in which heterogeneity was introduced. (For all the scenarios without heterogeneity, the ratio of Q/(k-1) was close to unity as expected, corresponding to I
2 = 0 [data not shown].)
- Abbreviations for Table and Legend: contr – control, exp – experimental, I
2 – I
2 heterogeneity measure, k – number of trials in each meta-analysis, n – number of experimental or number of control patients per trial, Q – Cochran's Q statistic for heterogeneity, MD – mean difference, RoM – ratio of means, s – standard deviation units, SMD – standardized mean difference.
