Beyond the Pill: Psychosocial and Behavioural Predictors of ART Non-Adherence Following the Single-Tablet Regimen Transition in Yaoundé, Cameroon

Achieving the UNAIDS 95-95-95 targets depends on optimal adherence to antiretroviral therapy (ART). While Cameroon transitioned to simplified Dolutegravir-based Single-Tablet Regimens (STR), the impact on adherence relative to Multiple-Tablet Regimens (MTR) remains to be elucidated. This hospital-based cross-sectional study among 680 participants at Yaoundé Jamot Hospital quantified adherence using a modified CPCRA 7-day recall and CASE Adherence Index. Results indicated an optimal adherence prevalence of 79.7% (95% CI: 76.4–82.7%) for the 7-day recall and 80.9% for the CASE Index. No significant difference in adherence was observed between STR and MTR users (p = 0.494). Multivariable modified Poisson regression revealed that lack of family support was the strongest predictor of non-adherence (aPR: 1.407, 95% CI: 1.203–1.646; p < 0.001). Other significant factors included depressive symptoms (aPR: 1.257, 95% CI: 1.036–1.525) and risky alcohol consumption (aPR: 1.158, 95% CI: 1.096–1.224). These findings suggest that in the era of simplified regimens, adherence is driven primarily by psychosocial and behavioural determinants rather than physical drug complexity. To bridge the final 20% gap, interventions must prioritize family support systems and mental health screening alongside pharmacological simplification.