Heterosexual women who have had a female sex partner in the past year report higher levels of substance use and other risk behaviors than do women who are homosexual, bisexual, exclusively heterosexual or heterosexual but with a less recent female partner, according to a study of 20–44-year-old National Survey of Family Growth respondents.1 Compared with women who are exclusively heterosexual, those who identify themselves as heterosexual but have had a recent female partner are more likely to smoke daily, drink weekly, binge drink, and use marijuana or cocaine. Furthermore, these women report a higher lifetime number of male partners than most of the other groups, and are more likely to have had a nonmonogamous male partner in the past year and to have had sex with a male while high.

The analytic sample consisted of 6,087 women aged 20–44 who had completed the 2002 National Survey of Family Growth. Weighted means and frequencies were calculated, and analysis of variance and chi-square tests were conducted to examine differences across groups defined by sexual identity and behavior; logistic and linear regression analyses assessed these differences while controlling for age, relationship status, and race or ethnicity.

Ninety-three percent of women said that they were heterosexual, including 85% who had had only male partners, 6% who had had a female sex partner more than a year ago and 2% who had done so in the past year. One percent of women self-identified as homosexual, 3% as bisexual and 4% as “something else.” About half of heterosexual respondents who reported any female partners said they were attracted only to males, compared with nine in 10 exclusively heterosexual respondents.

Among all groups, heterosexual women who had had a recent female partner had the lowest mean age (29 vs. 30–35). They were less likely to be married than women who were exclusively heterosexual and those who had had a nonrecent female partner (19% vs. 47–59%), and were more likely to be of Hispanic ethnicity than homosexual and bisexual respondents (15% vs. 3–9%).

In bivariate comparisons, heterosexuals with a recent female partner reported the highest levels of substance use; in adjusted comparisons with respondents who were exclusively heterosexual, they were more likely to smoke tobacco daily (46% vs. 19%), drink weekly (49% vs. 24%), binge drink (34% vs. 11%), and use marijuana (58% vs. 11%) or cocaine (19% vs. 2%). This group also reported higher levels of most of these activities than did homosexuals (the exceptions were binge drinking and weekly drinking), whereas they differed from bisexuals and heterosexuals with a non-recent female partner only in reporting more marijuana use.

The median lifetime number of male partners was 10 for heterosexuals who had had any female partner, whereas it was seven for bisexuals, four for women who were exclusively heterosexual and one for homosexuals; in contrast, the median lifetime number of female partners was one for heterosexual women reporting any female partner, while it was two for bisexuals and four for homosexuals. The prevalences of other risk behaviors among heterosexuals with a recent female partner were most similar to those among bisexuals and heterosexuals with a nonrecent female partner, yet significant differences with all groups were found. Heterosexual respondents who had had a recent female partner reported first intercourse at a younger age than all of the other groups except bisexual women (mean, 15 vs. 16–18 years), and were more likely than the other four groups to have had a nonmonogamous male partner in the past year (40% vs. 5–23%) and to have had sex with a male while high (69% vs. 7–47%). Furthermore, compared with women who were homosexual or exclusively heterosexual, heterosexual respondents with a recent female partner were more likely to report ever having had anal sex with a male (66% vs. 22–32%), having received a diagnosis of herpes (11% vs. 1–4%) and having had an STD test in the past year (45% vs. 8–21%). Finally, they were also more likely than exclusively heterosexual women to have engaged in sex work in the last year (6% vs. 2%) and to have had a bisexual male partner in the same period (5% vs. 2%).

The researchers note a number of limitations of their analysis: They could not distinguish whether respondents had had same-sex activity while they were high, whether they had engaged in this behavior in a one-on-one context, or whether they had had a single same-sex encounter or an ongoing relationship. Nonetheless, they believe that same-sex experience among heterosexual women may serve as an indicator for elevated levels of sexual risk behaviors—both recent and historical—and that in clinical and prevention settings, this information could help providers identify women who are at increased risk. The investigators believe that future research should more carefully examine how women are grouped according to their current and past sexual behavior, and that such efforts could help “build understanding of the complex intersections of sexual behavior, identity, and attraction … and elucidate the context, frequency, and implications of same-sex sexual experience in heterosexual women.”—J. Thomas