Drug and Alcohol Use with Condomless Anal Sex among Men Who Have Sex with Men in Melbourne, Australia: A Retrospective Data Analysis from 2011 to 2017.

Rises in condomless anal sex among men who have sex with men (MSM) have been reported over the last decade but there is less certainty about the role that drugs, alcohol, play in this change. We examined the changes in drug and alcohol use among 22,255 MSM reporting condomless anal sex at Melbourne Sexual Health Centre in 2011-2017. There was a 7% annual increase in using drugs before and/or during condomless anal sex but a 3% annual reduction in condomless anal sex while drunk. MSM taking PrEP were more likely to report condomless anal sex with drug use (AOR: 1.21; 95%CI: 1.07-1.37) and alcohol use (AOR: 1.29; 95%CI: 1.14-1.46) compared with MSM not taking PrEP.