Objective: To examine factors associated with heterosexual anal intercourse (AI).
Methods: Between 2001 and 2004, 1084 heterosexual adults aged 18 to 26 attending public sexually transmitted disease clinics in Seattle, New Orleans, and St Louis were interviewed using computer-assisted self interview and tested for STIs; Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, and genital herpes (HSV-2). Characteristics associated with AI were identified using logistic regression.
Results: Overall 400 (37%) reported ever having had AI, 266 (28.9%) reported AI with at least 1 of their last 3 partners, and 19% reported AI with their last partner. Fewer women than men reported condom use at last AI (26% vs. 45%, P <0.001). Ever having AI was associated with sex on the same day as meeting a partner [AOR 3.9 (95% CI, 2.46-6.21)], receiving money for sex [AOR 2.8 (1.40-5.45)], and >3 lifetime sex partners [AOR 2.8 (1.56-5.07)] among women, and sex on the same day as meeting a partner [AOR 2.0 (1.33-3.06]) among men. AI with the last partner was associated with sex toy use [AOR 5.6 (2.63-12.0)] and having concurrent partners [AOR 2.2 (1.21-4.11)] among men, and with sex within a week of meeting [AOR 2.4 (1.28-4.37)], believing the partner was concurrent (AOR 1.9 [1.12-3.22]), and sex toy use [AOR 5.7 (2.31-14.0)] among women. Prevalent vaginal and urethral sexually transmitted infections were not associated with AI.
Conclusions: Many young heterosexuals attending sexually transmitted disease clinics reported AI, which was associated with other sexual risk behaviors, suggesting a confluence of risks for HIV infection.