Human immunodeficiency virus infection and older adults: A retrospective single-site cohort study from Johannesburg, South Africa.

Introduction: HIV-infected adults aged over 50 years in South Africa are increasing. This study explored differences between baseline characteristics and 12-month outcomes of younger and older HIV-infected adults initiated on antiretroviral therapy (ART). Additionally, associations with outcomes within the older group were sought.

Methods: We retrospectively reviewed treatment-naive HIV-infected adult patients at ART initiation. Patients aged 18.0-39.9 years were compared to patients aged over 50 years using log-binomial regression for baseline characteristics and 12-month outcomes. Within the older group, outcome associations were found using multivariate regression.

Results: The older cohort (n = 1635) compared to the younger cohort (n = 10726) comprised more males (47.2% vs. 35.4%, PR 1.52, p < 0.05), smokers (12.9% vs. 9.7%, PR 1.32, p < 0.05) and overweight patients (26.0% vs. 20.0%, PR 1.32, p < 0.05). Fewer older patients had tuberculosis (10.2% vs. 15.3%, PR 0.67, p < 0.05), other opportunistic infections (16.9% vs. 23.3%, PR 0.70, p < 0.05), World Health Organization stage 3/4 disease (39.9% vs. 43.2%, PR 0.89, p < 0.05), anaemia (22.8% vs. 28.4%, PR 0.77, p < 0.05), liver dysfunction (17.1% vs. 21.3%, PR 0.83, p < 0.05) or low CD4+ count < 100 cells/mm³ (56.3% vs. 59.9%, PR 0.71, p < 0.05).Mortality was higher in the older cohort (11.3% vs. 7.5%, PR 1.48, p < 0.05). Virological suppression was greater in the older cohort (89.5% vs. 86.5%, PR 1.28, p < 0.05) but CD4+ restitution was lower (62.8% vs. 75.0%, PR 0.61, p < 0.05). There was no difference in treatment complications between the groups.Within the older cohort, associations with death were as follows: age > 55 years (PR 1.47, p < 0.05), an AIDS-defining condition (PR 2.28, p < 0.05), raised ALT (PR 1.53, p < 0.05) and CD4+ < 100 cells/mm³ (PR 2.15, p < 0.05). Associations with favourable treatment response at 12 months were unemployment (PR 1.18, p < 0.05) and raised ALT (PR 1.19, p < 0.05). Associations with a treatment complication at 12 months were unemployment (PR 1.12, p < 0.05), smoking (PR 1.20, p < 0.05) and nevirapine use (PR 1.36, p < 0.05) but secondary education was protective (PR 0.87, p < 0.05).

Conclusion: HIV-infected South African adults aged over 50 years differ in characteristics and outcomes compared to their younger counterparts and justify specialised management within HIV treatment facilities.