Longitudinal modeling of methamphetamine use and sexual risk behaviors in gay and bisexual men.

The purpose of the analyses was to examine the associations between methamphetamine and other club drug use with sexual risk taking across time in cohort of gay and bisexual men. Data were collected from a community-based sample. Assessments of unprotected anal intercourse with casual partners, and use of methamphetamine and other illicit drugs, were assessed at baseline, and at 4-month intervals over the course of a year, and were analyzed using hierarchical linear modeling. Methamphetamine use was related to the frequency of unprotected insertive and receptive intercourse with both HIV-positive and status unknown casual partners across time. The association between methamphetamine use and unprotected acts also was more pronounced for HIV-positive participants. These findings suggest that methamphetamine, and unprotected anal intercourse are co-occurring risk behaviors, that potentially heighten the risk of HIV transmission among gay and bisexual men. HIV prevention and intervention should concurrently target both these behaviors.