HIV, AIDS, and other health risks: findings from a multisite study--an introduction.

In late 1990 the National Institute on Drug Abuse (NIDA) initiated the Cooperative Agreement (CA) for AIDS Community-Based Outreach/Intervention Research Program. The goal of this program was to prevent the further spread of HIV among out-of-treatment drug users, in particular injection drug users (IDUs) and crack cocaine users, their sexual partners, and those at risk for initiating injection behavior. To accomplish this goal, the CA set out to monitor drug use and HIV risk behaviors, assess the efficacy of various HIV risk reduction interventions, and develop and refine outreach and intervention strategies. Twenty-three research sites, 21 rural and urban sites in the United States and one each in Puerto Rico and Brazil, were included in the CA program. This article presents an overview of the CA as well as a synopsis of the studies covered in this special issue examining the total CA database.