INTERVAL: Varying Intervals of ART to Improve Outcomes in HIV

This is an unblinded cluster-randomized study to evaluate the effectiveness of two strategies for scripting/dispensing of antiretroviral therapy (ART) on retention, virologic suppression, and cost compared to the standard of care. The study will be conducted in Malawi and Zambia among approximately 8,200 HIV-1-infected adults (18 years or older) who are stable on ART. Clusters will be randomized to one of three study arms: (1) standard of care (SOC) ART scripting (varies by country, region, clinic, and/or provider), (2) three-month ART scripting, and (3) six-month ART scripting. 30 clusters will be selected for the study, 15 in Malawi and 15 in Zambia, and will be randomized to a study arm.

This study will be conducted among approximately 8,200 HIV-infected individuals age 18 years or older who are stable on antiretroviral therapy (ART) in 30 clusters in Malawi and Zambia. Individuals will be screened at routine clinic visits and enrolled if they meet inclusion criteria. Enrolled individuals will receive standard of care at their site with the exception of their ART dispensing interval based on the assigned randomization. Outcomes will be assessed after 12 months, but all participants will be under observational follow-up for 36 months, with annual re-assessment of retention, virologic suppression, and cost-effectiveness. There will be no contact with study participants during the period of follow-up. Endpoints will be determined by chart review after the primary endpoint is reached (12 months). Endpoint data collection will include: 1. Retention in care on strategy 2. Suppressed viral load of \<1,000 copies done as part of standard of care viral load monitoring In a subset of participants in Malawi (n=1,500), we will perform a review of participants' health passports, a record of patient clinic visits, general health information, and medications that is possessed by patients in Malawi, after the 12-month endpoint has been completed. Data will be collected on interim clinic visits, such as reason for visit/services received (sick, family planning, non-communicable disease treatment), frequency of visits, and location of clinic services. In a subset of participants (\~240), we will perform a post intervention study visit after the 12-month endpoint is completed. Qualitative interviews will be performed with a subset of participants and will focus on patient experience with assigned dispensing interval, including challenges/barriers and facilitators towards adherence and retention. Focused questions around endpoints (if default, reasons; if virologic failure, reasons including adherence) will also be addressed in the post-intervention visit.