“…These associations with both injection and sexual risk factors are consistent with past research among PWID (Arasteh & Des Jarlais, 2009; Le Marchand et al, 2013; Matos et al, 2004), and studies that separately analyzed injection (Hottes, Bruneau, & Daniel, 2011; Stein et al, 2000; Stein, Charuvastra, Maksad, & Anderson, 2002; Wang et al, 2014) and sexual risk (Michael D Stein et al, 2002). These results also support polysubstance use research among PWID, such that co-use of alcohol and other injection drugs predict increased risk of injection and sexual behavior, compared to primary use of one substance (Harrell et al, 2012; Keen et al, 2014).…”