Table 2 Trade-off between increased woman-years (power) and falling adherence.
Scenario | Week | Adherence | Observed reduction in HIV incidence* | 95% CI | % power |
|---|---|---|---|---|---|
1. Adherence is unchanged from Week 40 to week 52 | 40 | 80% | 40% | (17%, 56%) | 85% |
| Â | 52 | 80% | 40% | (20%, 55%) | 90% |
| Â | 40 | 80% | 35% | (11%, 52%) | 72% |
| Â | 52 | 80% | 35% | (14%, 51%) | 80% |
| Â | 40 | 80% | 30% | (6%, 48%) | 55% |
| Â | 52 | 80% | 30% | (8%, 47%) | 64% |
2. Adherence drops to 50% at week 52 | 40 | 80% | 40% | (17%, 56%) | 85% |
| Â | 52 | 50% | 37% | (16%, 53%) | 86% |
| Â | 40 | 80% | 35% | (11%, 53%) | 72% |
| Â | 52 | 50% | 33% | (12%, 49%) | 75% |
| Â | 40 | 80% | 30% | (6%, 48%) | 55% |
| Â | 52 | 50% | 29% | (8%, 46%) | 66% |
3. Adherence drops to 0% at week 52 | 40 | 80% | 40% | (17%, 56%) | 85% |
| Â | 52 | 0% | 34% | (14%, 50%) | 79% |
| Â | 40 | 80% | 35% | (11%, 52%) | 72% |
| Â | 52 | 0% | 29% | (6%, 45%) | 63% |
| Â | 40 | 80% | 30% | (6%,48%) | 55% |
| Â | 52 | 0% | 25% | (2%, 42%) | 50% |