Quantifying delay in first contact with HIV programs among young women engaged in sex work in Mombasa, Kenya: a time-to-event analysis

BackgroundYoung women engaged in sex work (YSW) experience a disproportionately high burden of HIV, yet most HIV programs for sex workers are not designed to reach adolescent girls and young women. MethodsLongitudinal data from the start of sex work are infeasible, but cross-sectional surveys may help identify "contact gaps". We used data from the 2015 Transitions Study, a cross-sectional survey of sexually active women aged 14-24 who self-identified as a sex worker in Mombasa, Kenya. We created a virtual cohort using self-reported event timing described relative to the survey date. We quantified the time from self-identification as sex worker to the initial program contact ("contact gap") and employed time-to-event analyses to estimate and characterize factors associated with the rate of program contact. ResultsOf 392 YSW, 47 (12%) reported program contact, with a median time of 12 months (interquartile range: 2, 24). The rate of program contact per 100 person-months was 0.52 [95% confidence interval (CI): 0.38, 0.68], and when applied to the estimated population size of YSW in Mombasa, the minimum access gap was 11,532 person-years. A shorter contact gap was associated with: older age when first negotiated for sex (adjusted hazard ratio:1.2 [95%CI: 1.0, 1.5]); and self-perceived ease of earning money through sex work (11.5 [2.8, 47.7]). ConclusionA large contact gap highlights the need to reshape HIV prevention services for YSW across their life course. Despite limitations, cross-sectional data could help estimate the contact gap and support program monitoring and evaluation.