Non-injection substance use correlates with risky sex among men having sexwith men: data from HIVNET

Associations between substance use and sexual behavior were examined among 3220 seronegative men who have sex with men (MSM) in a HIV vaccine prepared ness study. Relationships between current and past substance use and curren t sexual risk were evaluated using crude odds ratios and logistic regressio n to adjust for confounding variables. Heroin and injection drug use were u ncommon (< 2%). Substances most often used were alcohol (89%), marijuana (4 9%), nitrite inhalants (29%), amphetamines or similarly acting stimulants ( 21%), cocaine 14% and hallucinogens (14%). Increased adjusted odds for unpr otected sex were significantly associated with current heavy alcohol use (O R 1.66; CI 1.18, 2.33), past alcohol problems (OR 1.25; CI 1.05, 1.48), and current drug use (OR 1.26; CI 1.08, 1.48). When associations with specific drugs and nitrite inhalants were examined separately, current use of cocai ne and other stimulants (OR 1.25; CI 1.01, 1.55), hallucinogens (OR 1.40; C I 1.10, 1.77), and nitrite inhalants (some (OR 1.61; CI 1.35, 1.92); heavy (OR 2.18; CI 1.48, 3.20)), were independently associated with unprotected s ex. Those with past drug use or past heavy alcohol use but not currently us ing demonstrated no increase in sexual risk, suggesting an important role f or substance-focused interventions in risk reduction efforts among MSM. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.