A Latent Class Analysis of Risk Factors for Acquiring HIV Among Men Who Have Sex with Men: Implications for Implementing Pre-Exposure Prophylaxis Programs.

Current Centers for Disease Control and Prevention (CDC) guidelines for prescribing pre-exposure prophylaxis (PrEP) to prevent HIV transmission are broad. In order to better characterize groups who may benefit most from PrEP, we reviewed demographics, behaviors, and clinical outcomes for individuals presenting to a publicly-funded sexually transmitted diseases (STD) clinic in Providence, Rhode Island, from 2012 to 2014. Latent class analysis (LCA) was used to identify subgroups of men who have sex with men (MSM) at highest risk for contracting HIV. A total of 1723 individuals presented for testing (75% male; 31% MSM). MSM were more likely to test HIV positive than heterosexual men or women. Among 538 MSM, we identified four latent classes. Class 1 had the highest rates of incarceration (33%), forced sex (24%), but had no HIV infections. Class 2 had <5 anal sex partners in the previous 12 months, the lowest rates of drug/alcohol use during sex and lower HIV prevalence (3%). Class 3 had the highest prevalence of HIV (7%) and other STDs (16%), > 10 anal sex partners in the previous 12 months (69%), anonymous partners (100%), drug/alcohol use during sex (76%), and prior STDs (40%). Class 4 had similar characteristics and HIV prevalence as Class 2. In this population, MSM who may benefit most from PrEP include those who have >10 sexual partners per year, anonymous partners, drug/alcohol use during sex and prior STDs. LCA is a useful tool for identifying clusters of characteristics that may place individuals at higher risk for HIV infection and who may benefit most from PrEP in clinical practice.