Purpose: To examine the event-level association between alcohol consumption and the likelihood of unprotected sex among college-age young adults considering contextual factors of partner type and amount of alcohol consumed.
Methods: A 30-day, Web-based, structured daily diary was used to collect daily reports of sexual behaviors and alcohol use from 116 sexually active young adults, yielding 2,764 diary records. Each day we assessed the prior evening's behavior regarding alcohol consumption, opportunities for sex, sexual intercourse, condom use, and contextual factors including type of sexual partner.
Results: Based on multilevel models, drinking proximal to events of sexual intercourse increased the likelihood of unprotected sex with casual but not steady partners. For women there was a positive association between number of drinks and a greater likelihood of unprotected sex with casual partners but a negative association with steady partners. Drinking during situations involving opportunities for sex with casual partners increased the likelihood of sex. For women especially, drinking more increased the likelihood of sex occurring regardless of partner type.
Conclusions: Failure to assess the contextual determinants of the alcohol-unprotected sex association may result in underestimates of the magnitude of this association. These data highlight an important area for intervention with young adults: reducing alcohol-involved sexual risk behavior with casual partners, especially among women.