HIV This Week

Smith AM, Grierson J, Pitts M, Pattison P. Individual characteristics are less important than event characteristics in predicting protected and unprotected anal intercourse among homosexual and bisexual men in Melbourne, Australia. Sex Transm Infect 2006;82:474-7.

Smith and colleagues described individual, social network and encounter specific factors associated with protected anal intercourse and unprotected anal intercourse. The cross sectional survey was conducted between April and November 2002. A total of 733 sexual encounters were reported by 202 men recruited from the gay community in Melbourne, Australia. Of the 733 sexual events most (56.3%) did not involve anal intercourse, and more involved protected anal intercourse than unprotected anal intercourse (30.6% versus 13.1%). Protected anal intercourse was more likely than no anal intercourse if the participant's social network was mostly homosexual, the partner was an occasional or casual partner, or was HIV positive. Protected anal intercourse was less likely if sex took place at a "beat" but more likely if it took place at a sauna. Protected anal intercourse was more likely if the partner was affected by drugs or alcohol. Unprotected anal intercourse was more likely than no anal intercourse if the participant had injected drugs in the year before interview. It was less likely if the partner was occasional or casual or was HIV positive but more likely if the partner's HIV status was unknown. Unprotected anal intercourse was much more likely than no anal intercourse if the encounter took place at a "sex on premises" venue. The authors conclude that in this analysis it is the characteristics of the sexual encounter that predict whether protected anal intercourse or unprotected anal intercourse rather than no anal intercourse takes place.

Editors’ note: Venues, social networks and other encounter specific factors can carry as much, if not more, weight in determining whether the sex is risky and how risky it gets.