Increasing proportions of Australian gay and homosexually active men engage in unprotected anal intercourse with regular and with casual partners.

We examined trends in sexual practice among gay and homosexually active men in Australia. Self-complete questionnaires were distributed with mail-order sex video catalogues in 2000 and returned anonymously through a reply-paid facility. The data were compared with those from men who responded to promotional material sent out with the same catalogues and who participated in national telephone surveys of men who have sex with men conducted in 1992 and 1996. A key independent variable was gay community attached (GCA) versus non-GCA (NGCA) derived from two items about number of gay friends and amount of free time spent with gay men. Responses came from 1,832 men ranging in age from 16 to 80 (median = 39) years. HIV status was 73% negative, 5% positive, 22% untested; 1,181 men were GCA and 651 men were NGCA. Overall, from 1992 to 2000 there was a significant upward trend in the proportion of men reporting any unprotected anal intercourse (UAI) in the previous six months with regular partners: 21.5%, 24.7%, 46.4% of the total sample (p < 0.001). And similarly for UAI with casual partners: 12.4%, 16.2%, 25.5% (p < 0.001). The upward trends in UAI-regular and UAI-casual were similar and significant (p < 0.001) for both GCA and NGCA men. These nationwide Australian data provide evidence of continuing increases in unprotected anal intercourse with regular and with casual partners. Whereas the majority of men do not engage in any unprotected anal intercourse during a defined interval, ever increasing proportions of them do.