Sparse digital adherence interventions in registered HIV trials with Latin American sites

Introduction: Digital tools can support antiretroviral adherence and retention in care, but the trials registered with Latin American sites have not been described. Methods: This descriptive cross-sectional study analysed ClinicalTrials.gov records of interventional HIV trials that started in 2012-2024 and had at least one site in 21 Latin American and Caribbean countries and territories. Trials of digital adherence or retention interventions for people living with HIV were identified by keyword screening and adjudication. Channel and behaviour-change components were coded from registry text, and outcome registration was appraised. Proportions are reported with Wilson 95% confidence intervals. Results: Of 277 registered trials, 8 (2.9%; 95% CI 1.5-5.6) tested a digital adherence or retention intervention, and none started before 2017. Text messaging or WhatsApp carried the intervention in 5 trials, and gamification was named in 1. An adherence outcome was registered in 6 trials, with an explicit threshold in 3. A viral load outcome was registered in 5 trials. Conclusions: Digital adherence interventions formed a small share of HIV trials registered with Latin American sites and were concentrated in small randomised trials of messaging. Thresholds for adherence and viral load, and results posting, were incomplete. Registrants should define adherence and viral load outcomes explicitly and post results.