|
Required Sample Size for High-Risk Group Patients with Two Interim Analyses
|
|---|
| |
Power = 80%
|
Power = 90%
|
|---|
| |
P0 = 80%
|
P0 = 70%
|
P0 = 80%
|
P0 = 70%
|
|---|
|
P1
|
N1
|
N2
|
Total
|
N1
|
N2
|
Total
|
N1
|
N2
|
Total
|
N1
|
N2
|
Total
|
|---|
|
70%
|
171
|
342
|
513
|
NA
|
NA
|
NA
|
237
|
474
|
711
|
NA
|
NA
|
NA
|
|
65%
|
79
|
158
|
237
|
833
|
1666
|
2499
|
109
|
218
|
327
|
1155
|
2310
|
3465
|
|
60%
|
45
|
90
|
135
|
213
|
426
|
639
|
63
|
126
|
189
|
295
|
590
|
885
|
|
55%
|
30
|
60
|
90
|
96
|
192
|
288
|
41
|
82
|
123
|
133
|
266
|
399
|
|
50%
|
21
|
42
|
63
|
54
|
108
|
162
|
29
|
58
|
87
|
75
|
150
|
225
|
|
45%
|
15
|
30
|
45
|
35
|
70
|
103
|
21
|
42
|
63
|
48
|
96
|
144
|
|
40%
|
12
|
24
|
34
|
24
|
48
|
72
|
16
|
32
|
48
|
33
|
66
|
99
|
|
35%
|
NA
|
NA
|
NA
|
17
|
34
|
51
|
NA
|
NA
|
NA
|
24
|
48
|
72
|
- P0: 30 days mortality rate in the standard arm. P1: 30 days mortality rate in the treatment arm
- N1: sample size for the standard care arm. N2: sample size for the treatment arm
- For 80% power: probability of rejection at each look: 1st look p < 0.002, futility look p > 0.835, 2nd look p < 0.014, futility look p > 0.312, final look p < 0.046
- For 90% power: probability of rejection at each look: 1st look p < 0.002, futility look p > 0.830, 2nd look p < 0.014, futility look p > 0.298, final look p < 0.046
- 1:2 randomization; ρ = 3.0
- Bold indicates recommended sample size with suggested parameters
