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.