HIV optimism does not explain increases in high-risk sexual behaviour among gay men in Scotland

Elford et al. [1] found that HIV optimism could not explain the increase in high-risk sexual behaviour among gay men in London. There was a similar increase in risk among Scottish gay men between 1999 and 2002 [2], and we investigate here whether HIV optimism can explain this. We compared rates of unprotected anal intercourse (UAI) with casual partners and the levels of HIV optimism in cross-sectional bar-based surveys of gay men in Scotland's two largest cities: Glasgow and Edinburgh (1999: N = 2498, response rate 77.5%; 2002: N = 1734, response rate 62.0%) [3,4]. HIV optimism was measured using two single-item scales (optimism 1: ‘I am less worried about HIV infection now that treatments have improved'; and optimism 2: ‘I believe that new drug therapies make people with HIV less infectious'). Men who agreed or strongly agreed with the items were categorized as optimistic and men who disagreed or strongly disagreed were categorized as not optimistic. ‘Unsure’ was included as a category in 1999, but men who responded ‘unsure’ or who had not answered these in either survey were excluded from the analyses (sample size: 1999 N = 1694, 2002 N = 1489). In 1999, 177 men (10.5%) reported UAI with casual partners compared with 268 (18.0%) in 2002 (P < 0.001). Most men were not optimistic, but HIV optimism did increase between the surveys. In 1999, 235 men (13.9%) agreed with optimism 1 compared with 345 (23.2%) in 2002 (P < 0.001); and 129 men (7.6%) agreed with optimism 2 compared with 186 (12.5%) in 2002 (P < 0.001). Overall, optimistic men were more likely to report UAI with casual partners than men who were not optimistic. For optimism 1, 19.6% of optimistic men (113/578) reported UAI with casual partners compared with 12.8% of men who were not optimistic (332/2599; P < 0.001). For optimism 2, the corresponding percentages were 21.1% (66/313) versus 13.2% (379/2864; P < 0.001). The unadjusted odds of UAI with casual partners were significantly higher in the 2002 survey compared with 1999, and among optimistic men compared with men who were not optimistic (Table 1). When entered into multivariate logistic regression, controlling for confounding factors, both survey year and optimism 1 remained significant; with no significant interaction between the two (P = 0.7; Table 1).Table 1: Unprotected anal intercourse with casual partners, survey year and HIV optimism: unadjusted and multivariate logistic regression.The analysis was repeated separately for men who had had an HIV test and those who had not. Never-tested men who engaged in UAI, by not knowing their own HIV status, were doing so with partners who may have been of discordant antibody status. However, even among tested men, only 20% always knew their casual partner's status, demonstrating that the majority of these men also engaged in non-concordant UAI. There were no significant differences in optimism between tested and never-tested men; HIV testing levels did not change between 1999 and 2002. The unadjusted odds of UAI with casual partners were significantly higher in the 2002 survey and among optimistic men for both groups (Table 1). When the multivariate models were run separately for tested and never-tested men, only the year of survey remained significant (Table 1). There was a significant interaction between survey year and optimism 1 for never-tested men [odds ratio (OR) 0.43, 95% confidence interval (CI) 0.20–0.94, P < 0.05]. Therefore, whereas the percentage of never-tested men reporting UAI with casual partners increased between 1999 and 2002, the rate of increase was greater among those who were not optimistic than among those who were. As has been found elsewhere [5], the majority of Scottish gay men were not optimistic. Optimistic men were more likely to report high-risk sexual behaviour than men who were not optimistic; an association that has been reported elsewhere [6–8]. However, both the year of survey and being ‘less worried about HIV infection now that treatments have improved’ were significantly and indepeependently associated with sexual risk in the multivariate analysis. If HIV optimism alone explained the increase in sexual risk, either the year of survey would not have remained significant or there would have been a significant interaction between year and optimism. In fact, the survey year remained significant after controlling for optimism and other confounding factors, and for the study groups as a whole there were no significant interactions between the survey year and optimism. Where there was an interaction, among never-tested men, the rate of increase was actually higher among men who were not optimistic than among those who were. Our results strongly suggest that HIV optimism cannot explain the recent increase in high-risk sexual behaviour among Scottish gay men; supporting the earlier findings for men in London [1]. Priority should be given to identifying other factors related to increased sexual risk.