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 |