Awareness of rectal microbicides was explored as a predictor of willingness to participate in rectal microbicide trials. As awareness of PREP was not asked about in the HIM study, awareness of NPEP, at either the enrolment interview or at the same interview as the last willingness to participate response, was explored as a predictor of

willingness to participate in trials using ARVs to prevent HIV infection. All were analysed by unconditional univariate logistic regression. P-values ≤0.05 were considered statistically significant. From June 2001 to December 2004, a total of 1427 participants were enrolled in the HIM study. The median age at enrolment was 35 years (range 18–75 years). The majority (95.2%) of participants self-identified as gay or homosexual. The cohort was Trametinib mouse highly educated, SB203580 with more than half (51.9%) holding university or postgraduate qualifications, and 21.6% with tertiary diploma or technical and further education (TAFE) degrees. Nearly two-thirds of participants (913; 65.7%) were somewhat or very involved in the gay community in Sydney. At the baseline interview, 477 participants

(33.5%) reported having UAI with a regular partner(s) only, 245 (17.2%) reported having UAI with casual partners and 521 participants (36.5%) reported no UAI in the last 6 months. A minority of participants (5.4%) reported that they had UAI with somebody known to be HIV positive in the last 6 months and nearly one-third (32.7%) reported that they had UAI only with HIV-negative partners. Of the 899 participants who answered questions on rectal microbicides in 2006 and 2007, only 123 (13.7%) had heard of rectal microbicides. Predictors of having heard of rectal microbicides

included older age (P=0.05) and having a higher level of education (P=0.001), and (nonsignificantly) greater gay community involvement (P=0.07) (Table 1). Previous hepatitis B vaccination (P=0.90), weekly income (P=0.90) and current risk behaviours [UAI in the past 6 months with a partner of unknown or positive HIV status ID-8 (P=0.71) or UAI with casual partners (P=0.96)] were not associated with knowledge of rectal microbicides. Almost one-quarter (24.4%) of HIM participants who responded (844) were likely or very likely to participate in rectal microbicide trials and over one-quarter (27.7%) did not know how likely they would be to participate. Overall, awareness of rectal microbicides was not related to likelihood of participation. However, after excluding the 233 men who reported that they did not know how likely they were to participate, awareness was significantly related to being unlikely to participate [odds ratio (OR) 0.78, 95% confidence interval (CI) 0.65–0.93, P=0.007].