Gay men who engage repeatedly in unprotected anal intercourse with casual partners: the Sydney Men and Sexual Health Study.

We set out to determine the frequency and correlates of gay men's repeated unprotected anal intercourse with casual partners (UAI-C), defined as UAI-C reported at each of 3 annual interviews. By May 1997, 659 men had completed 3 annual interviews for the Sydney Men and Sexual Health (SMASH) cohort study. For the 3 6-month periods prior to each interview, 127 men reported UAI-C during one period only; 45 reported it during 2 periods; and 20 men reported it during all 3 periods. These 20 men who had repeated UAI-C were compared with 497 men who had anal intercourse with casual partners but did not report on all 3 occasions that they had UAI-C. Logistic regression revealed that repeated UAI-C was associated with HIV-positive status, more casual partners, less favourable attitudes toward condoms and greater recreational drug use. Few gay men have repeated UAI-C but those who do run greater risk of HIV transmission.