Demographic and socioeconomic factors associated with ART nonadherence among 15 years and older South Africans: evidence from the 2022 cross-sectional population-based household survey

Globally, South Africa has the highest number of people living with HIV (PLHIV) and the largest HIV treatment programme. Adherence to antiretroviral therapy (ART) is a key factor in achieving viral load suppression and positive health outcomes and is, therefore, a crucial component in managing the HIV epidemic. The survey data were collected using a two-stage stratified cluster random sampling design. Descriptive statistics were used to summarize the sample characteristics including the prevalence of nonadherence to ART. Pearson chi-square was used to test for differences in categorical variables. Bivariate modified Poisson regression analysis was used to investigate factors associated with nonadherence to ART, and statistically significant variables were included in a multivariate modified Poisson regression model. Of 3737 participants who self-reported ever taking ART, 11.6% were classified as nonadherent (no antiretroviral [ARV] drugs detected in the dry blood spot). In the final model, participants with secondary or Grade 12 education had significantly higher prevalence of nonadherence than those with no or primary education (adjusted prevalence ratio [aPR] = 1.82; 95% CI: 1.12–2.95; p = 0.015). Decreased prevalence of ART nonadherence was associated with those aged 35–44 years (aPR = 0.48; 95% CI: 0.28–0.82; p = 0.007) and 55–64 years (aPR = 0.39; 95% CI: 0.18–0.84; p = 0.016) compared to those aged 15–24 years, and those residing in rural formal/farm areas compared to those living in urban areas (aPR = 0.27; 95% CI: 0.14–0.54; p < 0.001). The study highlights higher risk of nonadherence to ART among youth and those who reside in urban areas which could be improved through youth-friendly interventions and ongoing tailored interventions for PLHIV in urban areas.