“…Numerous studies have documented associations between drug and alcohol use and HIV transmission risk (Colfax et al, 2004); (Koblin, Chesney, Husnik, et al, 2003b; Mayer, Wang, Koblin, et al, 2014; Ostrow, Plankey, Cox, et al, 2009; Pappas & Halkitis, 2011; Sander, Cole, Stall, et al, 2013; Skeer, Mimiaga, Mayer, et al, 2012). However, MSM subpopulations are not homogenous and often exhibit different substance-use related risk profiles (Newcomb, Ryan, Greene, et al, 2014).…”