Table 1. Baseline socio-demographic, behavioural characteristics and HIV seroincidence—Individual and multivariable model results.
| Characteristic | Category | Enrolled Sample size | Contributed follow-up β (n = 5670) | # HIV seroconversions / # Woman-Years of Follow-up (incidence per 100 woman-years) | Univariable models # | Multivariable model # | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hazard Ratio | 95% CI Lower bound | 95% CI Upper bound | p-value | Hazard ratio | 95% CI Lower bound | 95% CI Upper bound | p-value | |||||
| Age (years) | Median (IQR) | 23 (20, 26) | ||||||||||
| Age (years) | ≤24 | 3603 (62.5%) | 3535 (62.3%) | 245 / 4749 (5.16) | 1.37 | 1.08 | 1.73 | 0.010 | 1.33 | 1.01 | 1.77 | 0.046 |
| >24 | 2165 (37.5%) | 2135 (37.6%) | 100 / 2898 (3.45) | Ref | ||||||||
| BMI (kg/m 2 ) | ≤30 | 3938 (68.3%) | 3869 (68.2%) | 256/5203 (4.92) | 1.34 | 1.05 | 1.71 | 0.018 | 1.33 | 1.01 | 1.74 | 0.041 |
| >30 | 1826 (31.7%) | 1797 (31.7%) | 89/2439 (3.65) | Ref | ||||||||
| Gravidity | Gravid | 4398 (76.2%) | 4335 (76.5%) | 255/5851 (4.36) | Ref | |||||||
| Nulligravid | 1370 (23.8%) | 1335 (23.5%) | 90/1796 (5.01) | 1.11 | 0.87 | 1.41 | 0.415 | 1.30 | 0.69 | 2.46 | 0.414 | |
| Living Children | None | 1605 (27.8%) | 1565 (27.6%) | 102/2110 (4.83) | 1.03 | 0.81 | 1.31 | 0.790 | 0.72 | 0.39 | 1.34 | 0.302 |
| At least one | 4163 (72.2%) | 4105 (72.4%) | 243/5537 (4.39) | Ref | ||||||||
| Living with Partner | No | 4856 (84.2%) | 4769 (84.1%) | 315/6415 (4.91) | 1.74 | 1.19 | 2.57 | 0.005 | 1.41 | 0.93 | 2.13 | 0.105 |
| Yes | 912 (15.8%) | 901 (15.9%) | 30/1232 (2.44) | Ref | ||||||||
| Unprotected Sex ! | Never | 1556 (27.0%) | 1528 (26.9%) | 91/2059 (4.42) | Ref | |||||||
| Sometimes-always | 4211 (73.0%) | 4141 (73.0%) | 254/5587 (4.55) | 1.04 | 0.81 | 1.32 | 0.770 | 1.03 | 0.79 | 1.34 | 0.832 | |
| New or Multiple Partners $ | No | 5209 (90.3%) | 5125 (90.4%) | 294/6930 (4.24) | Ref | |||||||
| Yes | 553 (9.6%) | 539 (9.5%) | 51/711 (7.18) | 1.68 | 1.24 | 2.27 | < .001 | 1.62 | 1.18 | 2.24 | 0.003 | |
| Coital Acts $ | ≤median (9) | 2990 (51.8%) | 2940 (51.9%) | 206/3941 (5.23) | 1.25 | 1.00 | 1.57 | 0.048 | 1.17 | 0.92 | 1.50 | 0.206 |
| >median (9) | 2777 (48.1%) | 2729 (48.1%) | 139/3704 (3.75) | Ref | ||||||||
| N. gonorrhoeae or C. trachomatis | Both negative | 4367 (75.7%) | 4294 (75.7%) | 235/5815 (4.04) | Ref | |||||||
| Either/both positive | 1389 (24.1%) | 1364 (24.1%) | 109/1815 (6.00) | 1.49 | 1.18 | 1.87 | < .001 | 1.42 | 1.11 | 1.81 | 0.006 | |
| HSV-2 Serology | Negative | 2874 (49.8%) | 2825 (49.8%) | 149/3824 (3.90) | Ref | |||||||
| Positive | 2226 (38.6%) | 2188 (38.9%) | 151/2941 (5.13) | 1.35 | 1.07 | 1.70 | 0.010 | 1.48 | 1.16 | 1.89 | 0.001 | |
!Never unprotected sex includes participants with no partner, no sex, or having sex but always using a condom in the previous three months. Any unprotected sex includes participants who had sex at least once and never, rarely, sometimes, or often used a condom in the previous three months.
$In 3 months prior to enrolment.
NOTE: HSV-2 EIA results are classified as follows: <0.90 = Negative, 0.90 to 3.50 = Indeterminate, >3.50 = Positive
β Median age 23, IQR (20,26). Four participants are missing data on BMI (total 0.07%). One participant is missing data on unprotected sex and coital acts. Six participants (total 0.11%) are missing data on new sex partners in the previous 3 months. 12 participants are missing data on N. gonorrhoeae and C. trachomatis (total 0.2%). N = 657 unknown or indeterminate HSV-2 results excluded.
# Separate Cox PH models for each cofactor adjusted for randomized arm and stratified by site. Multivariable model includes all baseline cofactors.