Sarcouncil Journal of Medical Sciences

Abstract: Despite significant advances in biomedical research, key populations worldwide continue to experience high rates of HIV and STI transmission, highlighting the need for efficient methods to expand preventive programs, including pre-exposure prophylaxis (PrEP) and regular STI testing and treatment. Effective technologies, such as active provider participation and modern service delivery methods that reach all community members, are needed to achieve desired outcomes. This systematic review synthesizes recent evidence (2019–present) on provider engagement strategies and delivery models for scaling HIV and STI prevention, with a focus on effectiveness, implementation outcomes, and equity. This study was conducted in accordance with PRISMA 2020 guidelines, searching PubMed/MEDLINE, Scopus, Web of Science, and Embase for peer-reviewed studies published from 2019 to 2026 that assessed provider-level engagement strategies or service delivery models for HIV and STI prevention. The extracted data were based on intervention characteristics, provider roles, study settings, and outcomes. This study quality was assessed using the Cochrane RoB 2 and ROBINS-I tools. Narrative synthesis was complemented by meta-analytic estimates where feasible. Seventy-three studies met the inclusion criteria, yielding six major points: task-shifting and differentiated service delivery, integration into primary care and sexual health services, digital and telehealth-enabled models, community-based and peer-led approaches, provider-level barriers and facilitators, and equity-focused delivery for key populations. Telehealth and community-based models demonstrated superior retention and acceptability compared with traditional clinic-based care. The results indicate that provider engagement, together with flexible delivery systems, is a primary driver of expanded HIV and STI prevention efforts, which require workforce development, digital system integration, and equitable implementation methods to succeed.