Sexual violence among a cohort of injection drug users

The objective of this study was to determine the prevalence of, and factors associated with, sexual violence in childhood, adolescence and adulthood, among injection drug using men and women. The Vancouver Injection Drug User Study is a prospective cohort of injection drug users (IDU) begun in 1996. The analysis included all individuals who completed the baseline questionnaire who responded to a question about sexual assault. Multivariate modeling was used to determine and to what extent a history of sexual violence at different ages is predictive of HIV risk and other health risk behaviors. HIV prevalence was calculated as the total current number of HIV-positive individuals in the cohort. Of the 1437 eligible individuals, 36% reported a lifetime history of sexual violence; 68% of women, and 19% of men (p<0.001). After adjusting for fixed sociodemographics, these individuals were more likely to have ever been in the sex trade, to knowingly share needles/rigs with HIV-positive people, to have attempted suicide, to have ever accidentally overdosed, to binge on alcohol, and to have been diagnosed with a mental disorder/disability. The prevalence of child sexual abuse in this cohort is 21%; 33% for women, and 13% for men. The data show a dose-response relationship between age at first sexual violence and most risk behaviors examined. These relationships are further mediated by gender. The prevalence of HIV among individuals who ever experienced sexual violence was 25%, compared to 19% among those who never experienced sexual violence (p=0.006). Sexual violence, and especially child sexual abuse, is highly prevalent among this cohort, particularly among women. Child sexual abuse has worse consequences for both genders than sexual violence later in life. Nevertheless, women and men are affected differently by sexual violence at different ages, and this has significant implications for health promotion programs, and specifically HIV prevention.