Prospective associations between alcohol and drug consumption and risky sex among female college students.

Females who ever had vaginal sex were interviewed annually in their first two years of college (n=386, ages 17 to 20 at study outset) and asked about risky sex behaviors and substance use. In year one, 60.2%(wt) had intoxicated sex, 31.4%(wt) had multiple sex partners, and 48.9%(wt) had unprotected sex (i.e., without a condom). At follow-up, high rates of persistence (86.0%, 52.7%, 78.8% respectively) and initiation (36.0%, 23.9%, 41.8%) were observed. In multiple logistic regression analyses, drug use and drinking were independently associated with having multiple sex partners. Intoxicated sex independently predicted condom non-use and multiple sex partners, and appeared to mediate the relationship between substance use and multiple sex partners. Implications for prevention and future research are discussed.