Abstract
HIV remains a significant public health burden worldwide, especially in developing countries, despite the availability of effective prevention and treatment modalities, namely PrEP and ART, respectively. HIV-related stigma is a significant barrier to the optimal uptake or adherence to ART or PrEP in vulnerable populations. Therefore, there is a need for effective interventions that can address HIV-related stigma and improve adherence to ART or PrEP in vulnerable populations. This systematic review aimed to identify interventions that can effectively reduce HIV-related stigma and improve adherence to ART or PrEP in vulnerable individuals. A systematic review methodology following the PRISMA guidelines was used. The sources of information included MEDLINE (via PubMed search engine), Embase, Scopus, Web of Science, CINAHL, and PsycINFO. Studies were eligible if they were randomized controlled trials (RCTs) or quasi-experimental studies investigating the effectiveness of any intervention addressing HIV-related stigma among persons living with HIV and improving ART/PrEP adherence. We adopted a narrative synthesis approach to present our findings. For quality appraisal of included studies, we used Cochrane Risk of Bias (RoB 2) tool.Eight RCTs, but no quasi-experimental studies, met the eligibility criteria. Among the seven RCTs on ART adherence, four investigated the effectiveness of cognitive behavioral components (two studies showing positive impact on stigma reduction and ART adherence). Other effective interventions that improved ART adherence while reducing HIV-related stigma included empowerment program and youth peer-mentoring. Only one study focused on PrEP (comprising motivational interviewing, client-centered counseling), which showed stigma reduction and PrEP adherence. Although many interventions have the promise of HIV stigma reduction while simultaneously improving medication adherence, larger scale studies are needed for generalizability. The heterogeneity in measurement instruments for ART/PrEP adherence underscores the need for standardized scales. Cognitive behavioral therapy, empowerment interventions, youth peer-mentoring, motivational interviewing, and client-centered counseling all show effectiveness in reducing HIV self-stigma, while simultaneously improving medication adherence. Future studies should consider the inclusion of diverse populations and refining interventions to address HIV- stigma, especially about PrEP. It is critical to incorporate validated measurement tools to enhance comparability across research endeavors to address the complex interplay between stigma and adherence. PROSPERO number: CRD42023455610.