Stimulant use patterns and HIV transmission risk among HIV-serodiscordant male couples.

Background: Substance use is strongly linked to HIV risk, and members of couples can have a powerful influence on each other's health behaviors. We examined whether couple-level patterns of stimulant use were differentially associated with engaging in condomless anal intercourse with primary partners and outside partners.

Methods: Members of HIV serodiscordant male couples (N = 117 couples, 232 men) completed surveys, and HIV-positive men had blood drawn for viral load.

Results: Results revealed that stimulant use by only one partner in the couple was associated with a decrease in the odds of engaging in condomless anal sex with one's primary partner (AOR = 0.09, 95% CI: 0.01, 0.89). When both partners reported stimulant use, the HIV-negative partner had an increase in the odds of condomless sex with outside partners (AOR = 6.68, 95% CI: 1.09, 8.01).

Conclusions: Understanding the role of couples' stimulant use patterns in HIV transmission risk is an important area for future research and intervention.