Infectious Disease · Medical Literature
Adapting mHealth Interventions to Improve Self-Management of HIV and Reduce Substance Use Among Emerging Adults in Zambia: Protocol for a Randomized Controlled Trial.
Abstract
Sub-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. This 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. The 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. Recruitment 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. This 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. ClinicalTrials.gov NCT06415357; https://clinicaltrials.gov/study/NCT06415357. DERR1-10.2196/99714.
Clinical relevance
Sub-Saharan Africa bears a disproportionate HIV burden, and emerging adults (ages 18–24) in Zambia face compounded risks of suboptimal ART adherence due to developmental factors—risk-taking behavior, identity exploration, shifting social supports—alongside comorbid substance use that further undermines virologic outcomes. Current standard ART counseling (SAC) is insufficient to address the intersection of adolescent development, substance use, and HIV self-management in low-resource settings where digital health infrastructure is expanding. This protocol is timely given the scale-up of mHealth platforms in sub-Saharan Africa and the urgent need for scalable, theory-driven interventions tailored to young people with HIV (YPHIV) in these contexts.
Key findings
1. Study population: 100 YPHIV aged 18–24 in Zambia will be randomized across four arms—SAC alone, mHC+SAC, MTM+SAC, and mHC+MTM+SAC—using the multiphase optimization strategy (MOST) factorial framework to isolate component-specific effects. 2. Intervention design: The Healthy Choices intervention (4-session, in-person, motivational interviewing–based) will be adapted for mobile delivery (mHC) via the Computerized Intervention Authoring System (CIAS), augmenting reach and scalability without requiring in-person clinical contact. 3. A complementary motivational text messaging (MTM) component will be developed and delivered via CIAS to provide between-session reinforcement, targeting both ART adherence and substance use reduction as co-primary behavioral endpoints. 4. Formative phase findings: Phase 1 qualitative focus group discussions were completed with 48 YPHIV in July 2024, providing empirical grounding for intervention adaptation; Phase 2 beta testing via a community advisory board preceded the pilot RCT launch in June 2025. 5. Primary outcomes assessed at baseline, 3 months, and 6 months include feasibility and acceptability (System Usability Scale and paradata of engagement patterns), ART adherence, viral suppression, and substance use; biomarkers of ART adherence and/or sexually transmitted infections will also be collected. 6. Note: As this is a protocol paper, no efficacy effect sizes, confidence intervals, p-values, or NNT/NNH are yet available; quantitative outcome data are pending trial completion.
Practice implications
Clinicians managing YPHIV in low-resource settings should recognize that standard ART counseling alone is likely inadequate for this developmental cohort and should advocate for or pilot mHealth adjuncts—particularly mobile motivational interviewing platforms and structured SMS-based reinforcement—as feasible, low-barrier complements to clinic-based care. The MOST optimization framework employed here provides a rigorous methodological model for identifying which digital intervention components (mHC, MTM, or combined) drive benefit, which should inform future resource allocation decisions before large-scale rollout. If pilot efficacy is demonstrated, clinicians and health systems in Zambia and comparable low-resource settings should prioritize integration of CIAS-delivered mHealth tools into existing HIV care cascades for 18–24-year-olds, with particular attention to dual-targeting of ART adherence and substance use as interrelated barriers to viral suppression.