Modelling adverse treatment outcomes of HIV-infected adolescents attending public-sector HIV clinics in Lusaka

Background: In resource-limited setting, there is scarce evidence comparing antiretroviral therapy (ART) outcomes among HIV-infected adolescents to that of other age groups. Methods and study design: We analysed data from 25 ART facilities in Lusaka District, comparing treatment-naive ART-eligible young adolescents (10-14 years), older adolescents (15-19) and young adults (20-24 years) initiating first-line ART to those aged 24 years or older. The adjusted relative risk (RR) of failure to achieve an adequate CD4 response (defined as failure to increase CD4 count by >= 50 cells/mm(3) at 6 months or by >= 100 cells/mm(3)) at 6 or 12 months after ART initiation was modelled using log-binomial regression. The effect of age group on mortality and loss to follow-up (LTFUP; >= 60 days since scheduled visit date) was estimated using adjusted Cox proportional hazards models, respectively. This was a routine retrospective design using program data. Results: Of the 94,023 patients initiating ART from May 2004 to February 2011, 1303 (1.4%) were young adolescents, 1440 (1.5%) were older adolescents and 5825 (6.2%) were young adults. 85,455 (90.9%) were 24 years or older at the time of ART initiation. Compared with adults, both young adolescents (RR: 0.88, 95% confidence interval [CI]: 0.76-1.01 at 6 months and RR: 0.80, 95% CI: 0.69-0.93 at 12 months) and older adolescents (RR: 0.82, 95% CI: 0.71-0.95 at 6 months) were less likely to achieve adequate CD4 response. No evidence of a difference in mortality risk was observed among older adolescents (hazard ratio [HR] 1.20, 95% CI: 0.93-1.56) compared with adults; however, there was a reduced risk of mortality in young adolescents compared with adults (HR: 0.61, 95% CI: 0.40-0.92). Young adolescents were less likely to be LTFUP following ART initiation (HR: 0.74, 95% CI: 0.59-0.92), while older adolescents and young adults were reported to be more likely to drop out of care (HR: 1.54 95% CI: 1.33-1.78; HR: 1.51 95% CI: 1.40-1.63 respectively). Conclusion: Older adolescents and young adults had poorer ART treatment outcomes, including failure to achieve adequate CD4 recovery and failure to remain in long-term care, when compared with adults. Interventions are necessary to help increase outcomes and retention in care. (C) 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.