Table 6 Sample size requirements for different scenarios. Sample size is calculated using 90% power and 5% alpha
From: Selecting patients for randomized trials: a systematic approach based on risk group
Strategy | Intervention rate | Event rate in control arm of trial | Sample size (pts. screened) for relative risk of 0.75 |
|---|---|---|---|
Treat high-risk (risk 10% +) | 52.60% | 34.6% | 1228 (2335) |
Treat high-risk (risk 25% +) | 27.20% | 52.9% | 624 (2294) |
Treat high-risk (risk 50% +) | 12.60% | 74.6% | 292 (2317) |
Treat all | 100.00% | 20.0% | 2504 (2504) |