Alcohol and drug use in the context of anal sex and other factors associated with sexually transmitted infections: results from a multi-city study of high-risk men who have sex with men in the USA.

Men who have sex with men (MSM) who use alcohol and drugs are at especially high risk for sexually transmitted infections (STIs); more information is needed about associated factors to improve risk reduction. We assessed reported STIs and demographic and event-level alcohol and drug use characteristics associated with STIs in a diverse, multi-city study in the USA of MSM who use substances. Improved risk reduction efforts are needed for this group as well as some initiatives tailored to men who are HIV positive, younger and use drugs (not alcohol) in the context of anal sex.