Table 3.

False recent seroconverters and protective effect of MC on HIV incidence as calculated using BED and AI separately

BED
Cut-off	0.325	0.733	0.900	1.51	1.89	2.27
Window period	3m (91.5d)	6m (183d)	9m (274d)	12m (366d)	15m (457d)	18m (549d)
False LTS (%)	0/3 (0)	1/12 (8.3)	5/21 (23.8)	5/32 (16)	2/34 (5.9)	3/47 (6.4)
95% CI	0 to 0.53	0.5 to 32	9.6 to 44	6 to 30	1 to 17	2 to 16
Observed false RS (%)	1/124 (0.8)	6/124 (4.8)	8/124 (6.5)	NC	NC	NC
95% CI	0.05 to 3.8	1.9 to 9.6	3 to 12
1Calculated false RS (%)	2.1	4.3	6.4	8.5	10.7	12.8
Tested RSs
Intervention - Control	6 - 10	12 - 27	15-30	23 - 48	33 - 62	42 - 79
Uncorrected effect (%)	43	58	53	55	49	50
95% CI	-57 to 84	19 to 80	13 to 77	26 to 75	23 to 67	27 to 66
2Correction
Intervention (%)	28	29	34	30	26	24
Control (%)	24	18	24	20	20	18
Total (%)	25	21	28	23	22	21
Corrected effect (%)	46	63	59	60	53	53
95% CI	NC	22 to 88	9 to 86	25 to 80	25 to 73	30 to 70
AI
Cut-off	31.6	80.5	90.0	94.0	96.0	NC
Window period	3m (91.5d)	6m (183d)	9m (274d)	12m (366d)	15m (457d)	18m (549d)
False LTS (%)	0/3 (0)	1/12 (8.3)	3/21 (14)	4/32 (13)	4/34 (12)	NC
95% CI	0 to 53	0.5 to 32	4 to 33	4 to 27	3.8 to 25
Observed false RS (%)	0/124 (0)	3/124 (2.4)	15/124 (12)	NC	NC	NC
95% CI	0 to 2.4	0.6 to 6.2	7 to 19
1Calculated false RS (%)	2.9	5.9	8.8	11.8	14.7	NC
Tested RSs						NC
Intervention - Control	3 - 11	10 - 19	18-31	26 - 44	33 - 62
Uncorrected effect (%)	74	50	45	44	50	NC
95% CI	19 to 100	-6 to 78	3 to 72	17 to 71	21 to 69
2Correction						NC
Intervention (%)	77	47	39	36	36
Control (%)	30	35	32	31	27
Total (%)	40	39	35	33	30
Corrected effect (%)	92	59	50	49	55	NC
95% CI	14 to 100	-14 to 100	-13 to 83	4 to 78	25 to 77

LTS: Long-term seroconverters

RS: Recent seroconverters

m: months

d: days

AI: Avidity index

NC: Not calculable

CI: Confidence interval

¹Estimated by linear regression (see Additional file 1)

²Correction for intervention and control = [N_HIV+(1-False RS)]/N_{tested recent}