P272 Age patterns of oral and anal sexual practices among heterosexual males and females: a cross-sectional survey in Melbourne, Australia

Background Oral and anal sex practices among heterosexuals are not well-studied. We aimed to explore these sexual practices among heterosexuals attending a sexual health clinic. Methods This cross-sectional survey was conducted at Melbourne Sexual Health Centre between March-April 2019. This survey asked questions on oral sex (fellatio or cunnilingus), anal sex and rimming in the previous 3 months among heterosexuals. Age was categorized by: 18–24; 25–34; and ≥35 years. Results There were 709 participants (333 males; 376 females) who were eligible and completed the survey, with a median age of 26 (IQR: 23–31) and 35% (n=250) born in Australia. Most participants had had vaginal sex (n=677; 95.5%), with a median of 2 (IQR: 1–3) vaginal sex partners, and half did not use a condom (n=358; 50.1%). 148 (20.8%) participants had had anal sex, with a median of 1 (IQR: 1–1) anal sex partner, with 63.5% (n=94) not using a condom. There were no significant differences in vaginal/anal sex partner number or condom use by gender. Being ≥35 years was associated with higher mean partner number for anal sex (ptrend=0.021) and being 18–24 years with higher mean partner number for vaginal sex (ptrend=0.027). Most participants (n=637, 89.8%) had received oral sex; this proportion did not differ by age group or gender. Females (n=351, 93.4%) were more likely to perform oral sex than males (n=275; 82.6% males) (p Conclusion Rimming and anal sex are practiced by one fifth or more of heterosexuals. Younger heterosexuals had higher numbers of vaginal sex partners, while older heterosexuals had higher numbers of anal sex partners and were more likely to perform rimming.