Possible scenarios of treatment ratios with corresponding number of participants and corresponding power
| Ratio salpingectomy with delayed oophorectomy:salpingo-oophorectomy | Salpingectomy with delayed oophorectomy (N) | Salpingo-oophorectomy (N) | Total (N) | Total with 10% dropout added (N) | Power (%) | |
| BRCA1 | 1:1 | 675 | 675 | 1350 | 1500 | 89 |
| 2:1 | 900 | 450 | 1350 | 1500 | 92 | |
| BRCA2 | 1:1 | 675 | 675 | 1350 | 1500 | 86 |
| 2:1 | 900 | 450 | 1350 | 1500 | 91 |