Table 1 Study size to obtain 80% statistical power in the proposed screening interventions for different baseline rates for invasive cervical cancer incidence assuming various marginal effects, when α = 0.05 and intervention to control ratio 1:1
From: Alternative technologies in cervical cancer screening: a randomised evaluation trial
Invasive cervical cancer incidence per 105 woman-years1 | RR | Woman-years in follow-up (intervention group); 1-sided test | Woman-years in follow-up (intervention group); 2-sided test |
|---|---|---|---|
5 | 0.5 | 820,000 | 1,020,000 |
5 | 0.7 | 2,467,000 | 3,097,000 |
10 | 0.5 | 410,000 | 510,000 |
10 | 0.7 | 1,233,000 | 1,548,000 |
15 | 0.5 | 273,000 | 340,000 |
15 | 0.7 | 822,000 | 1,032,000 |
20 | 0.5 | 205,000 | 255,000 |
20 | 0.7 | 617,000 | 774,000 |