Interest in using rectal microbicides among Australian gay men is associated with perceived HIV vulnerability and engaging in condomless sex with casual partners: results from a national survey.

Objective: We assessed interest in using rectal microbicides to prevent HIV transmission among gay men in Australia.

Methods: A national online survey was conducted in 2013. Interest in using rectal microbicides was measured on a seven-item scale (α=0.81). Factors independently associated with greater interest in using a microbicide were identified using multivariate logistic regression.

Results: Data were collected from 1223 HIV-negative and untested men. Mean age was 31.3 years (SD=10.8, range 18-65); 77% were born in Australia and 25% reported any condomless anal sex with a casual partner in the previous 6 months. Overall, there was moderate interest in using rectal microbicides (M=3.33, range 1-5). In multivariate analysis, greater interest in using microbicides was independently associated with being born outside Australia (adjusted OR (AOR)=1.59; p=0.009), greater self-perceived likelihood of becoming HIV positive (AOR=3.40; p<0.001), less uncertainty about the efficacy of microbicides (AOR=0.65; p=0.009), any condomless anal sex with casual partners in the previous 6 months (AOR=1.78; p=0.03) and ever having received postexposure prophylaxis (AOR=1.53; p=0.04). Interest in using microbicides was not associated with age, number of male sex partners or the HIV status of regular male partners.

Conclusions: Interest in using rectal microbicides was associated with self-perceived vulnerability to HIV, engaging in sexual practices that increase the risk of HIV acquisition and less uncertainty about the efficacy of microbicides. There appears to be a group of men who would benefit from, and are highly motivated to use, a rectal microbicide product.