Predictors of Antiretroviral Initiation, Retention in Care and Viral Load Suppression Among Adolescents and Young Adults in the Ekurhuleni District, South Africa: A Retrospective Cohort Analysis

We conducted a retrospective cohort analysis of routine programmatic data to identify predictors of antiretroviral therapy (ART) initiation, retention in care (RiC), and viral load suppression (VLS) among adolescents and young adults (AYA) aged 10–24 years living with HIV in the Ekurhuleni District, South Africa. Time-to-event outcomes were analysed using Cox proportional hazards regression models. Of the 6667 AYA diagnosed with HIV, 5271 (79.5%) were aged 20–24 years, 5754 (86.8%) were female, and 5430 (81.9%) initiated ART. The median time to ART initiation was 0.0 months (interquartile range [IQR]: 0.00–0.13), indicating that most AYA initiated ART on the same day as HIV diagnosis or within a few days thereafter. Time to ART initiation did not differ significantly across age groups (log-rank χ2(2) = 5.83, p = 0.054). Retention in care was suboptimal, with 56% retained in care at five years. Compared with AYA aged 10–14 years, those aged 15–19 years (adjusted hazard ratio [aHR] = 2.29, 95% confidence interval [CI]: 1.38–3.82; p = 0.001) and 20–24 years (aHR = 2.54, 95% CI: 1.55–4.18; p < 0.001) had a higher hazard of retention in care. AYA who were pregnant at ART initiation also had a higher hazard of retention than those who were not pregnant (aHR = 1.26, 95% CI: 1.13–1.42; p < 0.001). Although 81% of AYA achieved VLS, this proportion remained below the UNAIDS third 95 target of 95% viral suppression among people receiving ART. Compared with AYA aged 10–14 years, those aged 20–24 years had a higher hazard of VLS (aHR = 1.05, 95% CI: 1.03–1.07; p < 0.001). Compared with AYA who initiated ART at World Health Organization (WHO) clinical stage I, those at WHO stage II had a lower hazard of VLS (aHR = 0.76, 95% CI: 0.65–0.89; p = 0.001). These findings highlight the importance of age and clinical and pregnancy-related factors in HIV care outcomes among AYA. Targeted, AYA-centred interventions that support timely ART initiation, sustained engagement in care, and viral suppression are essential to improve treatment outcomes in this population.