A review of the literature on event-level substance use and sexual risk behavior among men who have sex with men.

In the United States, there continues to be high incidence of HIV infection among men who have sex with men (MSM), who represent 57% of new infections in 2009. While many studies report associations between non-injection substance use and sexual risk behavior among MSM, overall results are mixed. Summarizing these studies is difficult because researchers have used a variety of assessment periods for substance use and sexual behavior. We review the scientific literature on event-level measures, which assess substance use and sexual risk behavior immediately before or during a sexual encounter and provide the most precise link between these two behaviors. From January 2009 through March 2010, we searched four databases: Ovid (MEDLINE and PsycINFO), Web of Knowledge, and Sociofile. Across studies, results varied by substance with little within substance consistency or a lack of research except for two notable exceptions: methamphetamine and binge alcohol use. The findings underscore the importance of providing HIV risk-reduction interventions for substance-using MSM.