Table 2 interim analyses and potential recommendations of the DSMB to stop the trial for futility or efficacy, depending on the observed treatment effect (and associated P-value)
Interim analysis | Number of patients | Recommend stopping for futility if difference in mortality is smaller than | Recommend stopping for efficacy if difference in mortality is greater than |
|---|---|---|---|
1 | 100 | 0.02 (P > 0.83) | - |
2 | 200 | 0.04 (P > 0.60) | 0.22 (P < 0.001) |
3 | 300 | 0.06 (P > 0.28) | 0.14 (P < 0.007) |
4 | 400 | 0.08 (P > 0.12) | 0.11 (P < 0.022) |
5 (final) | 500 | - | 0.09 (P < 0.042) |