title: Modelling adverse treatment outcomes of HIV-infected adolescents attending public-sector HIV clinics in Lusaka.
abstract: 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
  We analysed data from 25 ART facilities in Lusaka District, comparing treatment-naïve 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/mm3at 6 months or by ≥ 100 cells/mm3) 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: University of Zambia, School of Public Health, P.O. Box 5010, Ridgeway Campus, Lusaka, Zambia.
authors.forename: I
authors.initials: I
authors.lastname: Fwemba
authors.affiliation: University of Zambia, School of Public Health, P.O. Box 5010, Ridgeway Campus, Lusaka, Zambia.
authors.forename: P
authors.initials: P
authors.lastname: Musonda
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000554:Ambulatory Care Facilities; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count / Q000706:statistics & numerical data; D002648:Child; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data; D017150:Public Sector; D012189:Retrospective Studies; D012306:Risk; D016896:Treatment Outcome; D055815:Young Adult; D015024:Zambia / Q000453:epidemiology
chemical_list: D019380:Anti-HIV Agents
keywords: Adolescents; Adverse; HIV clinics; HIV-infected; Modelling; Outcomes; Public sector; Treatment