A systematic review to identify the challenges of demonstrating efficacy of HIV behavioral interventions for men who have sex with men (MSM)

Background: Men who have sex with men (MSM) continue to be disproportionately impacted by HIV in the U.S. Numerous HIV behavioral interventions for MSM were conducted over the past 20 years, but only 8 are considered evidence-based by the CDC's Prevention Research Synthesis (PRS) project. This systematic review examines why MSM intervention studies did not demonstrate sufficient evidence for efficacy and describes the challenges of testing HIV interventions for MSM.

Methods: Eligible studies included US-based HIV/STD interventions specifically targeting MSM, behavioral and biologic outcomes related to HIV transmission with controlled trials, and publication dates between 1988 and June 2009. We evaluated studies using PRS's criteria for assessing the strength of findings, and quality of research design, study implementation, and data analyses.

Results: We identified 26 eligible studies: 18 (69%) did not meet PRS criteria. Common reasons included non-significant positive effects (n = 8, 44%), analytic sample sizes <40 per arm (n = 5, 28%), retention rate <60% per arm (n = 4, 22%) and follow-up assessment < 1 month post intervention (n = 4, 22%). Seven (39%) failed multiple PRS criteria.

Conclusions: Given that several MSM interventions failed primarily because of non-significant positive effects, this might suggest these interventions were under-powered or did not adequately address critical behavior determinants or contextual factors. Examining these potential gaps may inform the design of efficacious MSM interventions. Additionally, more resources are needed for improving research design and implementation, especially for recruiting and retaining study participants, and conducting longer term intervention evaluations.