Table 2. Cox Proportional Hazards and Competing Risks Regression Results.
| Cox Regression | Competing Risks Regression | Competing Risks Regression | ||||
| Time to HIV-1 Acquisition | Time to HIV-1 Acquisition | Time to Loss to Follow-up | ||||
| Variable | aHR (95% CI) | P value | aSHR (95% CI) | P value | aSHR (95% CI) | P value |
| Risk Behavior Category* | ||||||
| No Partner | Reference | Reference | Reference | |||
| One Partner, Protected | 1.45 (0.99–2.12) | 0.06 | 1.42 (0.96–2.11) | 0.08 | 0.86 (0.71–1.03) | 0.10 |
| One Partner, Unprotected | 1.26 (0.84–1.88) | 0.26 | 1.05 (0.69–1.60) | 0.80 | 1.11 (0.93–1.33) | 0.26 |
| Multiple Partners, Protected | 1.29 (0.69–2.40) | 0.42 | 1.04 (0.55–1.98) | 0.89 | 0.77 (0.59–1.01) | 0.06 |
| Multiple Partners, Unprotected | 2.41 (1.36–4.27) | 0.003 | 2.47 (1.33–4.58) | 0.004 | 0.50 (0.32–0.76) | 0.002 |
| Year category* | ||||||
| 1993–1995 | Reference | Reference | Reference | |||
| 1996–1998 | 0.65 (0.44–0.97) | 0.04 | 0.75 (0.50–1.13) | 0.17 | 1.25 (0.98–1.60) | 0.07 |
| 1999–2001 | 0.44 (0.26–0.72) | 0.001 | 0.71 (0.44–1.14) | 0.16 | 1.75 (1.36–2.24) | <0.001 |
| 2002–2004 | 0.26 (0.15–0.45) | <0.001 | 0.52 (0.32–0.87) | 0.01 | 1.36 (1.05–1.75) | 0.02 |
| 2005–2007 | 0.09 (0.04–0.20) | <0.001 | 0.18 (0.09–0.37) | <0.001 | 2.57 (2.04–3.24) | <0.001 |
| Workplace | ||||||
| Bar or guesthouse | Reference | Reference | Reference | |||
| Nightclub | 0.22 (0.12–0.42) | <0.001 | 0.32 (0.15–0.67) | 0.002 | 0.94 (0.75–1.18) | 0.61 |
| Home-based or other | 1.27 (0.49–3.24) | 0.62 | 0.92 (0.35–2.40) | 0.86 | 0.72 (0.48–1.07) | 0.10 |
| Charge category | ||||||
| Non-monetary exchange | Reference | Reference | Reference | |||
| Low charge | 0.89 (0.64–1.24) | 0.50 | 1.14 (0.82–1.59) | 0.44 | 0.98 (0.83–1.15) | 0.77 |
| Medium charge | 0.65 (0.30–1.37) | 0.26 | 0.78 (0.35–1.76) | 0.55 | 1.06 (0.81–1.39) | 0.66 |
| High charge | 1.04 (0.53–2.04) | 0.90 | 1.22 (0.55–2.68) | 0.62 | 1.05 (0.80–1.37) | 0.74 |
| Duration of sex work at enrollment | ||||||
| ≤1 year | Reference | Reference | Reference | |||
| >1–<4 years | 0.74 (0.50–1.10) | 0.13 | 0.92 (0.62–1.37) | 0.69 | 0.83 (0.70–0.99) | 0.04 |
| ≥4 years | 0.92 (0.61–1.38) | 0.68 | 1.21 (0.81–1.80) | 0.35 | 0.77 (0.64–0.93) | 0.007 |
| Age at enrollment | ||||||
| <23 years | Reference | Reference | Reference | |||
| 23–26 years | 1.10 (0.71–1.70) | 0.67 | 1.10 (0.70–1.72) | 0.68 | 0.86 (0.71–1.06) | 0.16 |
| 27–30 years | 0.85 (0.54–1.35) | 0.50 | 1.04 (0.64–1.69) | 0.86 | 0.70 (0.57–0.87) | 0.001 |
| >30 years | 0.67 (0.41–1.10) | 0.11 | 0.80 (0.49–1.31) | 0.37 | 0.71 (0.57–0.89) | 0.003 |
| Education category | ||||||
| Less than primary school | Reference | Reference | Reference | |||
| Completed primary school | 1.74 (1.16–2.61) | 0.007 | 1.47 (0.98–2.21) | 0.06 | 0.98 (0.82–1.16) | 0.79 |
| Secondary school or higher | 1.71 (1.10–2.64) | 0.02 | 1.53 (1.01–2.31) | 0.05 | 0.93 (0.77–1.11) | 0.41 |
| Muslim religion | 1.23 (0.74–2.03) | 0.42 | 1.12 (0.65–1.93) | 0.67 | 0.96 (0.78–1.19) | 0.70 |
| Alcohol use | 1.15 (0.79–1.67) | 0.47 | 1.18 (0.82–1.71) | 0.37 | 0.82 (0.70–0.96) | 0.02 |
| DMPA use* | 1.62 (1.17–2.25) | 0.004 | 1.57 (1.12–2.22) | 0.01 | 0.78 (0.66–0.94) | 0.007 |
| Pregnancy* | 1.12 (0.45–2.75) | 0.81 | 0.72 (0.28–1.82) | 0.48 | 2.29 (1.70–3.08) | <0.001 |
| Cervicitis* | 1.01 (0.63–1.64) | 0.95 | 0.90 (0.53–1.53) | 0.69 | 0.97 (0.73–1.30) | 0.86 |
| Vaginitis* | 1.21 (0.90–1.62) | 0.20 | 1.10 (0.81–1.49) | 0.53 | 1.10 (0.96–1.26) | 0.17 |
| Herpes simplex virus type 2* | 1.69 (0.94–3.03) | 0.08 | 1.96 (1.07–3.59) | 0.03 | 0.94 (0.78–1.14) | 0.54 |
| Douching behavior | ||||||
| No douching | Reference | Reference | Reference | |||
| Douching with water | 5.90 (1.81–19.23) | 0.003 | 3.66 (1.11–12.05) | 0.03 | 1.18 (0.89–1.55) | 0.25 |
| Douching with soap | 8.39 (2.64–26.62) | <0.001 | 4.41 (1.37–14.20) | 0.01 | 1.18 (0.91–1.52) | 0.20 |
| Recent gap in attendance >60 days* | 0.30 (0.22–0.42) | <0.001 | 0.54 (0.38–0.75) | <0.001 | 0.68 (0.59–0.79) | <0.001 |
aHR = adjusted hazard ratio, aSHR = adjusted subhazard ratio, CI = confidence interval, DMPA = depot medroxyprogesterone acetate.
*
Time-dependent covariate.