Abstract
Background
Stigma is an important factor in medication adherence, but the mechanisms linking stigma to adherence are not understood, despite having been examined across multiple populations using a variety of study designs. Guided by a stigma-coping framework, we tested a model in which enacted stigma predicts antiretroviral (ART) nonadherence through stigma avoidance strategies and socially motivated nonadherence.Method
All adults waiting to receive their ART prescriptions (N = 1979) during multiple days and times were recruited from two public clinics in Cape Town South Africa (2021-2024). Enacted stigma, clinic-based stigma, stigma avoidance strategies, and intentional nonadherence in social settings (socially motivated nonadherence) were assessed with validated measures. ART adherence was prospectively measured over 1 month using unannounced phone-based pill counts and HIV viral load was obtained by laboratory testing. Models were tested at varying levels of clinic-based stigma.Results
Nearly half (45%) of participants skipped taking ART in social settings during the prior month. Enacted stigma was significantly associated with greater stigma avoidance strategies, which predicted socially motivated nonadherence, which in turn predicted lower ART adherence. The indirect effects of stigma avoidance strategies and socially motivated nonadherence were significant. Results were replicated for predicting HIV viral load. Moderator analyses indicated that indirect effects of enacted stigma through socially motivated nonadherence were significant only at higher levels of clinic-based stigma.Conclusion
Stigma undermines ART adherence and viral suppression through stigma avoidance and socially motivated nonadherence, particularly in stigmatized clinic environments. Interventions should address both patient- and clinic-level strategies for stigma management.