mHealth Interventions to Promote HIV Self-Testing Among Key Populations: A Systematic Review of Effectiveness and Implementation Outcomes

Objectives: This systematic review synthesized evidence on the effectiveness and implementation outcomes of mobile health (mHealth) interventions supporting HIV self-testing (HIVST) among key populations, including uptake, linkage to care, and user experiences. Methods: Eight electronic databases and gray literature were searched. Eligible studies evaluated mHealth interventions designed to promote or support HIVST. Due to substantial methodological and contextual heterogeneity, findings were synthesized narratively. Results: Twenty-one studies from high-, middle-, and low-income settings were included. Interventions included SMS reminders, mobile applications, tele-counseling, and digital outreach platforms. Many studies reported increased HIVST uptake and high acceptability; however, evidence for linkage to care was limited. Study quality varied, with several trials at high risk of bias. Technical barriers, privacy concerns, and challenges in interpreting results were commonly reported. Conclusion: mHealth interventions appear promising for supporting HIVST among key populations, but current evidence remains limited and preliminary. More rigorous and long-term studies are needed.