Significance level = 0.05, Power = 0.8
| | | | |
| | | | |
Estimated power from simulation study
|
m
1
|
m
2
|
ϕ
1
|
ϕ
2
|
n
|
log t-test
|
M-W test
|
t-test
|
1
|
1.5
|
0.5
|
0.5
|
14
|
0.781
|
0.755
|
0.690
|
1
|
1.25
|
0.5
|
0.5
|
51
|
0.797
|
0.776
|
0.664
|
1
|
1.1
|
0.5
|
0.5
|
303
|
0.801
|
0.781
|
0.639
|
1
|
0.5
|
0.4
|
0.4
|
9
|
0.788
|
0.724
|
0.687
|
1
|
0.7
|
0.4
|
0.4
|
23
|
0.794
|
0.772
|
0.662
|
1
|
0.9
|
0.4
|
0.4
|
204
|
0.800
|
0.781
|
0.669
|
1
|
0.6
|
0.3
|
0.3
|
9
|
0.791
|
0.728
|
0.728
|
1
|
0.7
|
0.3
|
0.3
|
15
|
0.800
|
0.762
|
0.723
|
1
|
0.8
|
0.3
|
0.3
|
32
|
0.797
|
0.773
|
0.713
|
1
|
0.75
|
0.25
|
0.25
|
15
|
0.784
|
0.747
|
0.729
|
1
|
0.88
|
0.25
|
0.25
|
63
|
0.797
|
0.776
|
0.737
|
1
|
0.94
|
0.25
|
0.25
|
250
|
0.800
|
0.781
|
0.741
|
Significance level = 0.05, Power = 0.9
| | | | |
| | | | |
Estimated power from simulation study
|
m
1
|
m
2
|
ϕ
1
|
ϕ
2
|
n
|
log t-test
|
M-W test
|
t-test
|
1
|
1.5
|
0.5
|
0.7
|
23
|
0.888
|
0.873
|
0.847
|
1
|
1.25
|
0.5
|
0.7
|
87
|
0.898
|
0.883
|
0.910
|
1
|
1.1
|
0.5
|
0.7
|
530
|
0.900
|
0.886
|
0.992
|
1
|
0.5
|
0.6
|
0.4
|
14
|
0.890
|
0.872
|
0.800
|
1
|
0.7
|
0.6
|
0.4
|
40
|
0.897
|
0.882
|
0.875
|
1
|
0.9
|
0.6
|
0.4
|
383
|
0.900
|
0.886
|
0.993
|
1
|
0.6
|
0.5
|
0.3
|
16
|
0.896
|
0.874
|
0.867
|
1
|
0.7
|
0.5
|
0.3
|
28
|
0.894
|
0.877
|
0.897
|
1
|
0.8
|
0.5
|
0.3
|
65
|
0.896
|
0.880
|
0.946
|
1
|
0.75
|
0.4
|
0.25
|
29
|
0.892
|
0.875
|
0.906
|
1
|
0.88
|
0.4
|
0.25
|
131
|
0.898
|
0.882
|
0.970
|
1
|
0.94
|
0.4
|
0.25
|
537
|
0.900
|
0.883
|
0.998
|
- Here, m
1,m
2 are pre-specified untransformed median values for groups 1 and 2, with ϕ
1,ϕ
2 corresponding untransformed standard deviations. The column ‘n’ denotes the analytically derived sample size calculated using Eq. (4). Estimated powers are shown for a two-sample t-test of log-transformed outcomes (‘log t-test’), a Mann-Whitney U test of untransformed outcomes (‘M-W test’) and a two-sample t-test of untransformed outcomes (‘t-test’)