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Table 3 Power for comparison of HIV incidence in Arm A or B with Arm C, with 7 communities per arm and Population Cohort of 2,500 adults per community (assuming that on average 2,125 (85%) will be HIV-uninfected at baseline and that loss to follow-up will be 20% after 2 years and 25% after 3 years) with 5,206 person-years per community over 36 months

From: HPTN 071 (PopART): Rationale and design of a cluster-randomised trial of the population impact of an HIV combination prevention intervention including universal testing and treatment – a study protocol for a cluster randomised trial

HIV incidence rate/100 py (control arm) Between-cluster coefficient of variation (k) Effectiveness (%) Power (%)
1.0 0.15 25% 57%
1.0 0.15 30% 74%
1.0 0.15 35% 87%
1.0 0.15 40% 95%
1.0 0.15 45% 99%
1.0 0.15 50% 100%
1.0 0.15 55% 100%
1.0 0.15 60% 100%
1.0 0.15 65% 100%
1.0 0.20 25% 44%
1.0 0.20 30% 60%
1.0 0.20 35% 75%
1.0 0.20 40% 87%
1.0 0.20 45% 94%
1.0 0.20 50% 98%
1.0 0.20 55% 99%
1.0 0.20 60% 100%
1.0 0.20 65% 100%
1.5 0.15 25% 64%
1.5 0.15 30% 81%
1.5 0.15 35% 92%
1.5 0.15 40% 98%
1.5 0.15 45% 100%
1.5 0.15 50% 100%
1.5 0.15 55% 100%
1.5 0.15 60% 100%
1.5 0.15 65% 100%
1.5 0.20 25% 48%
1.5 0.20 30% 65%
1.5 0.20 35% 80%
1.5 0.20 40% 91%
1.5 0.20 45% 96%
1.5 0.20 50% 99%
1.5 0.20 55% 100%
1.5 0.20 60% 100%
1.5 0.20 65% 100%