Correlates of condomless anal intercourse among men who have sex with men in Santiago de Chile.

Men who have sex with men (MSM) are disproportionally affected by the HIV epidemic globally. In Chile, HIV prevalence among MSM is estimated at 20%, and condomless anal intercourse is the predominant mode of HIV transmission. This cross-sectional study aimed to estimate a broad array of characteristics in a sample of Chilean MSM including condomless anal intercourse (CLAI), as well as to explore possible associations between these characteristics and CLAI. MSM were recruited through respondent-driven sampling between June and October of 2016. A final sample size of 246 MSM was analyzed using CLAI as the outcome and sociodemographic, clinical and sexual risk behavior characteristics as exposure variables. Results show that close to half of the participants reported CLAI with casual sex partners during the last six months, and this outcome had an increased risk associated with use of drugs prior to sex and having had >5 sexual partners.