Digital health promotion strategies to increase HIV testing uptake among key populations: a scoping review.

HIV testing uptake among key populations remains suboptimal despite its central role in HIV prevention. Digital health promotion strategies have been increasingly implemented to address multilevel barriers to testing. However, current evidence is fragmented across platforms, populations, and settings. This scoping review aimed to map and synthesize current evidence on digital health promotion strategies designed to increase HIV testing uptake among key populations. This scoping review adopted Arksey & O'Malley's five-stage framework and reported the process following PRISMA-ScR. PubMed, Scopus, the Cochrane Library, and CINAHL were searched for studies published from January 2015 to April 2025. Eligible studies examined digital health promotion strategies focused on HIV testing uptake among key populations. Sixteen studies were included. We identified four thematic clusters of digital health promotion strategies. Overall, the identified approaches showed potential to increase testing uptake and reduce barriers; however, evidence remains heterogeneous and uneven across populations and settings. Digital strategies for HIV testing are complementary. Integrating mobile apps, social media outreach, digital messaging, and peer-driven networks may offer scalable, context-sensitive solutions for key populations. However, the limited representation of certain groups, particularly transgender women and people who inject drugs, highlights important gaps in the evidence base. Further studies with more robust design, wider geographic coverage, and longer follow-up are warranted.