title: Age at antiretroviral therapy initiation predicts immune recovery, death, and loss to follow-up among HIV-infected adults in urban Zambia.
abstract: We analyzed the association of age at antiretroviral therapy (ART) initiation with CD4(+) T cell count recovery, death, and loss to follow-up (LTFU) among HIV-infected adults in Zambia. We compared baseline characteristics of patients by sex and age at ART initiation [categorized as 16-29 years, 30-39 years, 40-49 years, 50-59 years, and 60 years and older]. We used the medication possession ratio to assess adherence and analysis of covariance to measure the adjusted change in CD4(+) T cell count during ART. Using Cox proportional hazard regression, we examined the association of age with death and LTFU. In a secondary analysis, we repeated models with age as a continuous variable. Among 92,130 HIV-infected adults who initiated ART, the median age was 34 years and 6,281 (6.8%) were aged ≥50 years. Compared with 16-29 year olds, 40-49 year olds (-46 cells/mm(3)), 50-59 year olds (-53 cells/mm(3)), and 60+ year olds (-60 cells/mm(3)) had reduced CD4(+) T cell gains during ART. The adjusted hazard ratio (AHR) for death was increased for individuals aged ≥40 years (AHR 1.25 for 40-49 year olds, 1.56 for 50-59 year olds, and 2.97 for 60+ year olds). Adherence and retention in care were poorest among 16-29 year olds but similar in other groups. As a continuous variable, a 5-year increase in age predicted reduced CD4(+) T cell count recovery and increased risk of death. Increased age at ART initiation was associated with poorer clinical outcomes, while age <30 years was associated with a higher likelihood of being lost to follow-up. HIV treatment guidelines should consider age-specific recommendations.
authors.affiliation: 1 Centre for Infectious Disease Research in Zambia , Lusaka, Zambia .
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Vinikoor
authors.forename: Jessica
authors.initials: J
authors.lastname: Joseph
authors.forename: Jonas
authors.initials: J
authors.lastname: Mwale
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Marx
authors.forename: Fastone M
authors.initials: FM
authors.lastname: Goma
authors.forename: Lloyd B
authors.initials: LB
authors.lastname: Mulenga
authors.forename: Jeffrey S A
authors.initials: JS
authors.lastname: Stringer
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Eron
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Chi
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000401:mortality; D006801:Humans; D008875:Middle Aged; D010349:Patient Compliance; D011379:Prognosis; D014505:Urban Population; D055815:Young Adult; D015024:Zambia
chemical_list: D019380:Anti-HIV Agents