We evaluated the relationship between frequency and number of substances used and HIV risk [ie, serodiscordant unprotected anal intercourse (SDUAI)] among 3173 HIV-negative substance-using MSM. Compared with nonusers, the adjusted odds ratio (AOR) for SDUAI among episodic and at least weekly users, respectively, was 3.31 [95% confidence interval (CI), 2.55 to 4.28] and 5.46 (95% CI, 3.80 to 7.84) for methamphetamine, 1.86 (95% CI, 1.51 to 2.29) and 3.13 (95% CI, 2.12 to 4.63) for cocaine, and 2.08 (95% CI, 1.68 to 2.56) and 2.54 (95% CI, 1.85 to 3.48) for poppers. Heavy alcohol drinkers reported more SDUAI than moderate drinkers [AOR, 1.90 (95% CI, 1.43 to 2.51)]. Compared with nonusers, AORs for using 1, 2, and ≥3 substances were 16.81 (95% CI, 12.25 to 23.08), 27.31 (95% CI, 18.93 to 39.39), and 46.38 (95% CI, 30.65 to 70.19), respectively. High-risk sexual behaviors were strongly associated with frequency and number of substances used.
*San Francisco Department of Public Health, San Francisco, CA;
†Department of Epidemiology and Biostatistics,
‡Division of HIV/AIDS, and
§Department of Psychiatry, University of California San Francisco, San Francisco, CA; and
‖Division of HIV/AIDS Prevention, National Center for HIV/AIDS Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control, Atlanta, GA.
Correspondence to: Glenn-Milo Santos, MPH, San Francisco Department of Public Health, 25 Van Ness Avenue, Suite 500, San Francisco, CA 94102 (e-mail: email@example.com).
Supported by the Centers for Disease Control and Prevention, under cooperative agreement UR6PS000684 to Public Health Foundation Enterprises, City of Industry, CA.
The authors have no conflicts of interest to disclose.
The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the US Centers for Disease Control and Prevention.
Received January 29, 2013
Accepted March 22, 2013