Effectiveness of SMS Appointment Reminders on Antiretroviral Therapy Adherence and Viral Load Suppression in Khayelitsha, South Africa: A 12-Month Cohort Study

Poor adherence to antiretroviral therapy (ART) is a major barrier to viral load suppression for people living with HIV in sub-Saharan Africa. Missed clinic appointments contribute substantially to this problem. This study evaluated the effectiveness of an SMS-based appointment reminder system on improving ART adherence and viral load suppression at a primary healthcare clinic in Khayelitsha, South Africa. A 12-month prospective cohort study was conducted. Participants were randomised into an intervention group receiving automated SMS reminders before appointments and a control group receiving standard care. The primary outcome was the proportion achieving viral load suppression (<1000 copies/mL) at 12 months. Secondary outcomes included appointment attendance and self-reported adherence. The intervention group showed a statistically significant improvement in viral load suppression compared to the control group (78% vs. 65%). Appointment attendance was also higher in the intervention group (92% vs. 84%). SMS-based appointment reminders were an effective intervention for improving ART adherence and viral load suppression in this high-burden, resource-limited setting. Integration of SMS reminder systems into routine HIV care in similar primary healthcare contexts is recommended. Future research should explore the cost-effectiveness and long-term sustainability of such programmes. HIV, antiretroviral therapy, adherence, SMS reminders, mHealth, viral load suppression, South Africa This study provides empirical evidence from a resource-constrained African setting supporting the use of a low-cost technological intervention to improve HIV treatment outcomes.