Contemporary Disengagement From Antiretroviral Therapy in the Western Cape, South Africa: A Cross-Sectional Study.

IntroductionSouth Africa has the largest antiretroviral therapy (ART) programme in the world, with universal access available through the public health system. Yet, gaps in coverage persist. In the Western Cape (WC), an estimated 200,000 people living with HIV are not currently on ART-many of whom are known to the health services. Exploring how people who are not on ART differ from those who are on ART may help guide more effective strategies for re-engagement and retention in care.MethodsWe conducted a cross-sectional analysis of routine person-level data from the WC Provincial Health Data Centre, including adults (≥15 years) known to be living with HIV who accessed public services between October 2022 and September 2024. ART status was inferred from visit and dispensing records. Relative risks (RRs) of current disengagement were estimated using multivariable log-binomial regression on 25 imputed data sets, adjusting for sex, age, years since diagnosis, diagnosis setting and baseline CD4 count.ResultsOf 494,071 adults included, 131,368 (27%) were currently disengaged from ART. Those at elevated risk included men (aRR 1.20, 95% CI 1.19-1.21), younger people aged 15-24 years (aRR 1.54, 95% CI 1.51-1.57), those with CD4 >500 cells/mm3 at diagnosis (aRR 1.26, 95% CI 1.24-1.28) and individuals diagnosed in hospital (aRR 1.41, 95% CI 1.39-1.43) or during pregnancy (aRR 1.20, 95% CI 1.18-1.22). However, the majority of those disengaged were not from these groups, proportionally representing the underlying population living with HIV. Model discrimination was poor (AUC 0.614), indicating that these characteristics do not reliably identify those disengaged.ConclusionsMost disengaged individuals are from larger, lower-risk demographic groups and would be missed by interventions targeting higher-risk demographics. Whole-population strategies that address common barriers to retention through more inclusive, person-centred care offer the greatest potential to improve ART coverage.