Trends and associated factors in HIV testing among heterosexual men and women in Melbourne, Australia, 2011-2020

Background: Despite the increase in the proportion of HIV notifications attributed to heterosexuals in Australia, little is known about their HIV testing behaviours. We investigated the trends and factors associated with HIV testing behaviours among heterosexuals. Methods: We analysed the trend and proportion of heterosexuals attending the centre for the first time between 2011 and 2020, who had ever tested and tested for HIV in the past 12 months and the median number of months since their last HIV test. We identified factors associated with HIV testing behaviours using univariable and multivariable logistic regressions. Results: Of the 78 652 heterosexuals included, 53.1% were men and 46.9% were women. Overall, the proportion of heterosexuals who had ever tested for HIV was 40.8%, with a declining testing trend from 40.2% in 2011 to 36.5% in 2020 (Ptrend < 0.001). Overall, the proportion of heterosexuals tested for HIV in the past 12 months was 15.7%, with no significant change from 15.3% in 2011 to 14.7% in 2020 (Ptrend = 0.489). The median number of months since the last HIV test decreased from 18.0 (IQR 6.9-37.3) in 2011 to 15.0 (IQR 6.4-32.5) in 2020 (Ptrend < 0.001). Individuals who had condomless sex with casual partners (aOR 0.92, 95% CI 0.88-0.96) and who were diagnosed with a sexually transmitted infection (aOR 0.88, 95% CI 0.84-0.93) were less likely to have ever tested for HIV. Conclusions: HIV testing was low among heterosexuals, and individuals who engaged in condomless sex and had another sexually transmitted infection were less likely to be tested. To reduce HIV transmission, strategies to improve HIV testing among heterosexuals are needed.