Predictors of sharing drugs among injection drug users in the South Bronx: implications for HIV transmission.

HIV may be transmitted in the process of sharing injected drugs, even if all participants have their own syringes. In an effort to gain understanding of the extent and predictors of drug sharing, data were obtained via personal interviews with 1,024 injection drug users from four neighborhoods in the South Bronx. The relationship between drug-sharing and demographic, sexual, and drug-related variables was first examined in a bivariate analysis, and then via multiple logistic regression. Individuals who split drugs were more likely to be female, have had sex with a casual partner, exchanged sex for drugs or other needs, recently smoked crack cocaine, and shared needles. They were less likely to live or inject at their own home or have used a new needle the last time they injected. In a final logistic model, correlates of drug sharing included trading sex, injecting outside one's home, and using borrowed, rented or shared needles. Despite the lack of significance for gender in the final logistic model, females were at high risk of drug sharing because they constituted the great majority of those who exchanged sex. Continuing research is needed to understand how drug-sharing contributes to the spread of HIV and other infections, as are studies of approaches to reducing drug sharing. Prevention strategists and outreach organizations should be aware of the HIV risks inherent in the widespread practice of drug sharing.