Antiretroviral therapy adherence, virologic and immunologic outcomes in adolescents compared with adults in southern Africa

Abstract

Objective: To determine adherence to and effectiveness of antiretroviral therapy (ART) in adolescents vs. 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 = 7622) initiating ART between 1999 and 2006 and having a viral load measurement within 1 year after ART initiation.

Main outcome measures: Primary: virologic suppression (HIV viral load < or = 400 copies/mL), viral rebound, and CD4 T-cell count at 6, 12, 18, and 24 months after ART initiation. Secondary: adherence assessed by pharmacy refills at 6, 12, and 24 months. Multivariate analyses: loglinear 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, and 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% confidence interval: 1.31 to 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 with 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.

Conflict of interest statement

Conflict of interest

consultant: R.E. Chaisson (Bristol-Myers Squibb). Honoraria: J.B. Nachega (GlaxoSmithKline, Merck-Sharp-Dohme for continuing medical education lectures) and G. Maartens (Merck-Sharp-Dohme). Grants received: G. Maartens (Merck-Sharp-Dohme). Other: J.B. Nachega (Aspen Pharmaceuticals for conferences and travel grants).

Figures

Figure 1

Times to rebound, adolescents versus adults. P for log-rank test

Figure 2

Times to rebound, comparing adolescents to young adults (20–29 years old) and adults (≥30 years old).