Adapting mHealth Interventions to Improve Self-Management of HIV and Reduce Substance Use Among Emerging Adults in Zambia: Protocol for a Randomized Controlled Trial.

backgroundSub-Saharan Africa remains the region most affected by the HIV epidemic, with Zambia experiencing a substantial burden of disease. Young people with HIV are disproportionately impacted. Emerging adulthood (ages 18-24 years) is characterized by increasing independence, risk-taking behaviors, identity exploration, and changing social supports, all of which may impact HIV self-management, including medication adherence and retention in care. Substance use may further undermine HIV outcomes. Innovative interventions targeting HIV self-management and substance use reduction among Zambian young people are urgently needed.

objectiveThis study aims to develop and pilot a multicomponent mobile health (mHealth) intervention to improve HIV self-management and reduce substance use among young people in Zambia. We will adapt the 4-session in-person Healthy Choices intervention for mobile delivery (mobile Healthy Choices [mHC]) to increase access and delivery. We will also develop motivational text messaging (MTM) to enhance intervention impact. Both components will be delivered using the Computerized Intervention Authoring System. Using the multiphase optimization strategy (MOST) framework, we will assess preliminary efficacy and identify the most effective components.

methodsThe study includes 3 phases. Phase 1 will involve conducting focus groups with Zambian young people with HIV to explore barriers and facilitators of HIV self-management and substance use to inform intervention adaptation. Phase 2 will involve adaptation and beta testing of mHC and MTM for functionality and feasibility using a community advisory board. Phase 3 will consist of a pilot trial using the MOST framework to evaluate feasibility, acceptability, and preliminary efficacy of intervention components. A total of 100 young people with HIV will be randomized to one of four experimental conditions: (1) standard antiretroviral therapy (ART) counseling (SAC), (2) mHC+SAC, (3) MTM+SAC, and (4) mHC+MTM+SAC. Primary outcomes will include feasibility, acceptability, ART adherence, viral suppression, and substance use. Feasibility and acceptability will be assessed through paradata of use patterns and the System Usability Scale. Participants will complete assessments at baseline and at 3- and 6-month follow-up visits. Biomarkers of ART adherence and/or sexually transmitted infections will also be collected.

resultsRecruitment for this study began in May 2024 for phase 1. Focus group discussions were completed with 48 young people with HIV in July 2024. Phase 3, the pilot feasibility trial, began in June 2025. Upon project completion, we will have developed an innovative mHealth intervention to support HIV self-management and reduce substance use among Zambian young people with HIV.

conclusionsThis study addresses a critical problem-suboptimal ART adherence, substance use, and challenges with HIV self-management-among young people with HIV in Zambia. We are developing 2 technology-based, theory-driven intervention components aimed at improving HIV self-management and substance use outcomes. If successful, this study will pave the way for scale-up of mHealth interventions to improve HIV care outcomes among young people with HIV in Zambia and other low-resource settings.

trial registrationClinicalTrials.gov NCT06415357; https://clinicaltrials.gov/study/NCT06415357. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/99714.