Feasibility, acceptability and effectiveness of digital health interventions targeting the HIV care cascade among mobile populations: a mixed methods systematic review

Geographic mobility increases the risk of HIV acquisition and disengagement from HIV care. Digital technologies can deliver flexible, scalable and location-independent HIV care. However, the feasibility, acceptability and effectiveness of digital interventions for mobile populations has not been systematically appraised. We conducted a mixed methods systematic review of digital health interventions targeting the HIV care cascade among mobile populations. Using PRISMA and Joanna Briggs Institute guidelines, we searched PubMed, Web of Science and EBSCOhost for English peer-reviewed studies published between January 2010 and July 2024. Included studies assessed digital health interventions addressing at least one HIV care cascade step and focusing on mobile populations. Two reviewers independently screened titles and abstracts followed by full-text screening and data extraction. Data analysis and syntheses followed the convergent segregated approach. Of 2851 records identified, 21 studies were included evaluating 15 interventions. Interventions were categorized as non-internet-based (n=7); internet-based (n=2) and combined innovations (n=6). Most (n=10) focused on HIV testing only, with fewer addressing both HIV testing and linkage to care (n=3), linkage to care (n=1) or retention (n=1) only. Non-internet-based interventions, commonly used in low- and middle-income countries, were feasible across settings but encountered challenges related to network coverage, inactive SIMs and limited device access. Internet-based and combined approaches were feasible in high-connectivity contexts with social media achieving high reach among marginalized groups. Acceptability was high overall, particularly for interventions offering personalized, culturally relevant content that avoided an exclusive focus on HIV. Non-internet-based interventions using one-way, and bi-directional SMS significantly improved HIV testing, and phone calls and SMS improved linkage to care. Combined innovations showed limited effectiveness despite high reach. Digital health interventions using SMS and phone calls show promise for improving HIV testing and linkage to care among mobile populations, but success depends on tailoring to local infrastructure and user contexts.