Table 4 The total number of people needed (with 1:1 randomisation) for detecting a given reduction in risk with 90% power and a significance level of 0.025 (one-sided)
|  | Cumulative number of cases/1000 over 2 years of follow-up | ||
|---|---|---|---|
RR | 30/1000 | 40/1000 | 50/1000 |
0.4 | 2664 | 1982 | 1574 |
0.5 | 4106 | 3054 | 2424 |
0.6 | 6834 | 5082 | 4032 |