AIDS Res Hum Retroviruses. 2014 Jul 6. [Epub ahead of print] 24998881
Vinikoor MJ, Joseph J, Mwale J, Marx MA, Mulenga L, Stringer JS, Eron JJ, Chi B
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, 60 years and older (P for trend<0.001). 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/mm3), 50-59 year olds (-53 cells/mm3), and 60+ year-olds (-60 cells/mm3) 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 higher likelihood of being lost to follow-up. HIV treatment guidelines should consider age-specific recommendations.