Substance use patterns and factors associated with changes over time in a cohort of heterosexual women at risk for HIV acquisition in the United States

Background—Substance use is associated with HIV sexual risk behaviors, yet few studies have examined substance use patterns longitudinally. We evaluated the types and frequency of substances used over a six-month period among U.S. women at risk for HIV acquisition. Methods—Women reporting unprotected sex with a man in the previous six months and at least one other personal or partner HIV risk characteristic enrolled in a multisite cohort study and completed interviews about substance use at study visits. Prevalence and frequency of substance use at the baseline and six-month visits were compared and correlates of decreased substance use at the six-month visit were assessed. Results—Of 2,099 women enrolled, 1,882 had substance use data at baseline and six-months. Of these, 76.1% reported using at least one drug or binge drinking in the previous six months; 37.5% were frequent and 38.6% non-frequent substance users. Binge drinking was most frequently reported (63.3%), followed by cocaine (25.0%) and opioids (16.5%). Fifty-five percent of opiate users and 30% of cocaine users reported daily/almost daily use. At the six-month visit, 40.5% reported a decrease in frequency of use. Adjusting for income and type of drug used, polysubstance users were less likely to decrease frequency of use compared to those who only used one substance. Conclusion—A substantial decrease in frequency of substance use over time was observed in this cohort. Poly-substance users were less likely to reduce frequency of use over time, suggesting that specific substance use interventions targeting these users are warranted