Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
O’Brien-Fleming Stopping Boundaries (for p-values) and Maximum Sample Sizes for 1-β = 0.80, RRR=2.0, interim analysis after f=0.50 accrual, and each of pre-specified Type I error rates, α = 0.10 and 0.20.
| OF Stopping Boundaries | ||||
|---|---|---|---|---|
| α | Early efficacy (c1) |
Early futility (c2) |
Overall efficacy (d) |
Max N |
| 0.10 | 0.0200 | 0.4566 | 0.0940 | 101 |
| 0.20 | 0.0699 | 0.5765 | 0.1803 | 65 |
