Reducing HIV risk behavior among injection drug users: effect of methadone maintenance treatment on number of sex partners.

Some studies have found that sex-related HIV risk behavior is less common among drug users in treatment than among users not in treatment; other studies have found no such relationship. However, past studies have not controlled for drug-user background characteristics that might confound the relationship between treatment and risk behavior. Among this sample of injection drug users in Los Angeles, those enrolled in methadone maintenance treatment report fewer past-year sex partners than those not in treatment; among treatment clients, number of past-year partners is negatively related to time in treatment. These findings persist after age and other background characteristics are controlled. Path analyses suggest that treatment may reduce sex-risk behavior by facilitating clients' disengagement from paid sex and raising their perceived self-efficacy for risk reduction.