Background: Anal sex is an important yet little studied HIV risk behavior for women.
Methods: Using information collected on recent sexual encounters, we examined the influence of sex partner and relationship characteristics on the likelihood of engaging in anal sex among women with a high risk of HIV infection.
Results: Anal sex was nearly 3 times more common among actively bisexual women (OR = 2.96, 95% CI: 2.17-4.03). Women were more likely to have anal sex with partners who injected drugs (OR = 2.32, 95% CI: 1.44-3.75), were not heterosexual (OR = 1.85, 95% CI: 1.18-2.90), and with whom they exchanged money or drugs for sex (OR = 1.79, 95% CI: 1.10-2.90). The likelihood of anal sex also increased with the number of nights sleeping together (OR = 1.15, 95% CI: 1.06-1.24). In contrast, emotional closeness and social closeness were not associated with anal sex. Condom use during anal sex was uncommon, and did not vary according to partner or relationship characteristics.
Conclusions: Our findings support the need for HIV prevention interventions that target anal sex among heterosexuals, particularly in drug-using populations residing in neighborhoods with elevated levels of HIV prevalence.