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.

Effect of sex and age on outcomes among HIV-2-infected patients starting antiretroviral therapy in West Africa

“…Individuals initiating ART after 2007 in our cohort had higher mortality than those initiating ART earlier. This result contrast with findings from other HIV-1 studies, reporting a tremendous decline in mortality and LTFU with the scaling up of ART programs (12,29,30). One possible explanation for our finding could be the potential for the lower likelihood of being captured in programmatic databases for patients who started ART prior to 2007, and died or who were lost to follow up soon after entering care, compare to patients who survived.…”

“…Many other surveys from SSA reported similar or higher rates of LTFU among HIV-1 infected individuals receiving ART (14,17,18,30). In these studies, LTFU was associated with age at ART initiation, male sex, low BMI, low haemoglobin level and sometimes with low CD4 count at ART initiation (14,17,18,30).…”

“…Age is another cofactor frequently cited to explain the difference in mortality among ART-receiving men and women. Many surveys identified the older age of men compared with women at ART initiation, as a reason for sex-difference in mortality (9,13,14,30). In our cohort, more men than women initiated ART after the age of 50 and this age difference could also partly explain the difference in mortality between men and women.…”

Loss to Follow-up Trends in HIV-Positive Patients Receiving Antiretroviral Treatment in Asia From 2003 to 2013

“…This is consistent with Africa cohorts where retention in care is lowest among the ≤30 age group and highlights the need to engage adolescents and young adults 47 . In contrast with European and US HIV studies, we did not see greater retention in those aged >50 years at ART initiation 48 .…”

Predictors of Retention in HIV Care Among Youth (15–24) in a Universal Test-and-Treat Setting in Rural Kenya

“…Prior to guidelines for universal treatment, HIV-infected youth who started ART were more likely to be lost to follow-up 4–6 , report lower adherence 4,6 , and were more likely to have detectable viral loads than older age groups 4,5,7 . After two years of universal HIV testing and treatment in rural east Africa as part of the Sustainable East Africa Research in Community Health (SEARCH) trial, 82% of all adults with HIV in intervention communities were virally suppressed compared to only 67% of those age 15–24 8 .…”