Table 2.
Sub-group analyses: the associations between PrEP initiation and HIV risk-related sexual behaviors, by sex of the HIV-uninfected partner
| Males, n = 635 | Females, n = 307 | Interaction p | |||
|---|---|---|---|---|---|
| MD/PP (95% CI) | p | MD/PP (95% CI) | p | ||
| Mean number of sex acts with study partner, past month (MD) | |||||
| PrEP initiation | − 1.59 (− 2.00 to − 1.19) | < 0.001 | − 0.73 (− 1.19 to − 0.27) | 0.002 | 0.008 |
| Time since PrEP initiation | |||||
| 1-month | − 1.45 (− 1.99 to − 0.92) | < 0.001 | − 0.47 (− 1.08 to 0.14) | 0.13 | 0.73 |
| 3-months | − 0.62 (− 1.18 to − 0.06) | 0.03 | − 0.37 (− 0.99 to 0.25) | 0.24 | 0.03 |
| 6-months | − 1.17 (− 1.74 to − 0.59) | < 0.001 | − 0.03 (− 0.67 to 0.60) | 0.92 | 0.88 |
| 12-months | − 1.53 (− 2.03 to − 1.04) | < 0.001 | − 0.80 (− 1.36 to − 0.25) | 0.004 | 0.16 |
| > 12-months | − 2.29 (− 2.74 to − 1.83) | < 0.001 | − 1.16 (− 1.66 to − 0.65) | < 0.001 | – |
| Any condomless sexa with study partner, past month (PP) | |||||
| PrEP initiation | − 32% (− 35% to − 28%) | < 0.001 | − 27% (− 32% to − 22%) | < 0.001 | 0.08 |
| Time since PrEP initiation | |||||
| 1-month | − 37% (− 41% to − 33%) | < 0.001 | − 30% (− 36% to − 23%) | < 0.001 | 0.02 |
| 3-months | − 33% (− 38% to − 29%) | < 0.001 | − 22% (− 28% to − 16%) | < 0.001 | < 0.001 |
| 6-months | − 32% (− 37% to − 28%) | < 0.001 | − 29% (− 35% to − 22%) | < 0.001 | 0.14 |
| 12-months | − 29% (− 33% to − 25%) | < 0.001 | − 26% (− 32% to − 20%) | < 0.001 | 0.14 |
| > 12-months | − 29% (− 32% to − 25%) | < 0.001 | − 29% (− 34% to − 23%) | < 0.001 | – |
| Any sex with non-study partner, past month (PP) | |||||
| PrEP initiation | − 1% (− 3% to 1%) | 0.18 | 1% (0% to 3%) | 0.10 | 0.07 |
| Time since PrEP initiation | |||||
| 1-month | − 2% (− 5% to 0%) | 0.09 | − 1% (− 3% to 1%) | 0.37 | 0.51 |
| 3-months | − 3% (− 6% to 1%) | 0.02 | 1% (− 1% to 3%) | 0.52 | 0.34 |
| 6-months | − 2% (− 5% to 0%) | 0.10 | 1% (− 1% to 3%) | 0.38 | 0.66 |
| 12-months | − 1% (− 3% to 2%) | 0.62 | 2% (0% to 4%) | 0.03 | 0.95 |
| > 12-months | 0% (− 2% to 2%) | 0.92 | 2% (1% to 4%) | 0.01 | – |
Associations measured using individual longitudinal data and linear regression models with fixed effects for individuals, fertility intentions (trying, not trying, pregnant), sex with a non-study partner (study partner outcomes only), treatment for a genital infection, use of hormonal contraception, calendar month, and number of sex acts (any condomless sex outcome only)
MD mean difference, CI confidence interval, P p value, n number of participants, PP percentage point change
aParticipant reports having condomless sex with study partner at least once in the past month