  
% 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

10/10

5

0

4

0

0

5

1

95

97

95

90

92

90

15

11

14

15

13

14

59

48

55

 
10

0

5

0

1

5

0

95

97

95

92

93

92

27

22

26

19

18

19

60

48

56

 
30

0

5

0

1

6

0

94

96

95

94

94

94

66

61

64

39

38

38

60

48

56

MD = 8

100/100

5

0

0

0

0

0

1

96

97

96

88

88

87

82

82

82

21

21

21

93

92

92

RoM = 1.08
 
10

0

0

0

0

0

0

96

96

96

92

92

91

99

99

99

27

27

28

93

92

92

 
30

0

0

0

0

0

0

96

96

96

94

94

94

100

100

100

56

58

59

93

92

92

SMD = 0.5

10/10

5

0

4

0

0

5

0

95

97

95

90

92

90

64

57

62

43

40

42

59

48

56

 
10

0

5

0

0

5

0

95

97

95

92

93

92

91

89

90

66

64

65

60

48

56

 
30

0

5

0

0

6

0

94

96

94

94

93

93

100

100

100

98

97

97

60

47

57

MD = 20

100/100

5

0

0

0

0

0

1

96

97

96

88

88

88

100

100

100

61

61

61

93

92

92

RoM = 1.2
 
10

0

0

0

0

0

0

96

96

96

92

92

91

100

100

100

85

86

86

93

92

92

 
30

0

0

0

0

1

0

96

96

96

94

94

93

100

100

100

100

100

100

93

92

92

SMD = 0.8

10/10

5

0

4

0

0

5

0

95

97

95

90

92

90

95

94

95

75

72

73

59

47

56

 
10

0

5

0

0

5

0

95

96

95

92

92

92

100

100

100

95

95

95

60

47

57

 
30

0

5

1

0

6

0

94

94

94

94

92

93

100

100

100

100

100

100

60

46

57

MD = 32

100/100

5

0

0

0

0

0

1

96

96

96

88

88

87

100

100

100

91

91

91

93

92

92

RoM = 1.32
 
10

0

0

0

0

0

1

96

96

96

92

92

91

100

100

100

100

100

100

93

91

92

 
30

0

0

0

0

1

0

96

96

96

94

94

93

100

100

100

100

100

100

93

91

92

 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 (10/10 and 100/100 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/(k1) 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 metaanalysis, 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.