Objective To determine adherence to and effectiveness of ART in adolescents versus adults in southern Africa Design Observational cohort study Setting Aid for AIDS, a private-sector disease-management program in southern Africa Subjects Adolescents (age 11–19 years; n=154) and adults (n=7,622) initiating ART between 1999 and 2006 and having a viral-load measurement within one year after ART initiation Main Outcome Measures Primary: virologic suppression (HIV viral load ≤400 copies/mL), viral rebound and CD4+ T-cell count at 6, 12, 18, 24 months after ART initiation. Secondary: adherence assessed by pharmacy refills at 6, 12 and 24 months. Multivariate analyses: log-linear regression and Cox proportional hazards. Results A significantly smaller proportion of adolescents achieved 100% adherence at each time point (adolescents: 20.7% at 6 months, 14.3% at 12 months, 6.6% at 24 months; adults: 40.5%, 27.9%, and 20.6% at each time point, respectively; p<0.01). Patients achieving 100% 12-month adherence were significantly more likely to exhibit virologic suppression at 12 months, regardless of age. However, adolescents achieving virologic suppression had significantly shorter time to viral rebound (adjusted hazard ratio 2.03; 95% CI 1.31–3.13; p<0.003). Adolescents were less likely to experience long-term immunologic recovery despite initial CD4+ T-cell counts comparable to adults. Conclusions Compared to adults, adolescents in southern Africa are less adherent to ART and have lower rates of virologic suppression and immunologic recovery and a higher rate of virologic rebound after initial suppression. Studies must determine specific barriers to adherence in this population and develop appropriate interventions.

Virologic outcomes improve in a linear dose-response manner as adherence to NNRTI-based regimens increases beyond 50%.

It is unclear how adherence to highly active antiretroviral therapy (HAART) may best be monitored in large HIV programs in sub-Saharan Africa where it is being scaled up. We aimed to evaluate the association between HAART adherence, as estimated by pharmacy claims, and survival in HIV-1-infected South African adults enrolled in a private-sector AIDS management program. Of the 6288 patients who began HAART between January 1999 and August 2004, 3805 (61%) were female and 6094 (97%) were black African. HAART adherence was >or=80% for 3298 patients (52%) and 100% for 1916 patients (30%). Women were significantly more likely to have adherence>or=80% than men (54% vs 49%, P<0.001). The median (interquartile range) follow-up time was 1.8 (1.37-2.5) years. As of 1 September 2004, 222 patients had died-a crude mortality rate of 3.5%. In a multivariate Cox regression model, adherence<80% was associated with lower survival (relative hazard 3.23; 95% confidence interval: 2.37-4.39). When medication adherence was divided into 5 strata with a width of 20% each, each stratum had lower survival rates than the adjacent, higher-adherence stratum. Among other variables tested, only baseline CD4+ T-cell count was significantly associated with decreased survival in multivariate analysis (relative hazard 5.13; 95% confidence interval: 3.42-7.72, for CD4+ T-cell count200 cells/microL). Pharmacy-based records may be a simple and effective population-level tool for monitoring adherence as HAART programs in Africa are scaled up.