Table 1.
National Surgical Adjuvant Breast and Bowel Project trial C-08 (NSABP C-08) interim monitoring bounds in terms of one-sided P -values
| Interim analysis | Estimated time, years | Stop for futility if right-sided P -value < | Stop for superiority if left-sided P -value < | Number of events | Estimated accrual at interim |
|---|---|---|---|---|---|
| 1 |
2.0 |
0.05 |
0.00025 |
148 |
2,006 |
| 2 |
2.5 |
0.25 |
0.0005 |
~220 |
2,632 |
| 3 |
3.0 |
0.5 |
0.001 |
~312 |
2,632 |
| 4 |
3.5 |
0.5 |
0.001 |
~398 |
2,632 |
| 5 |
4.0 |
0.5 |
0.001 |
~473 |
2,632 |
| 6 |
4.5 |
0.5 |
0.001 |
~538 |
2,632 |
| Final | 5.0 | N/A | ~0.0246 | 592 | 2,632 |