Men and women in Britain report many differences in the characteristics of their heterosexual partnerships, and some differences in partnership characteristics are reflected in the likelihood of risky behavior. For example, men are more likely than women to have casual partners, and they are less likely than women to have partners of roughly their own age. Condom use is more likely in casual partnerships than within marriage; even so, the level of use in casual relationships suggests that many men and women are inadequately protected against the risk of STD infection. Additionally, condom use the first time a couple has sex is more likely if the partners are about the same age than if the male is five or more years older than the female. In nearly one-quarter of men's new partnerships, but only one in 10 of women's, first sex with a new partner occurs within 24 hours after the couple's meeting. These are among the findings of an analysis based on data from Britain's 1999–2001 National Survey of Sexual Attitudes and Lifestyles.1

The survey was based on a stratified probability sample of more than 11,000 British residents aged 16–44, who participated in face-to-face interviews and computer-assisted self-interviews. A total of 9,598 respondents reported having had at least one heterosexual partner in the past year; investigators used data on this subsample to study partnership formation, and they employed logistic regression to assess associations between partnership characteristics and condom use.

Men and women differed significantly in both the number and the types of heterosexual partners they reported for the previous year. On average, men reported 1.8 partners, whereas women reported 1.3; some 6% of men, but only 2% of women, had had five or more partners. The largest proportion of men's relationships (39%) were with a casual—or, in the survey's term, “not (yet) regular”—partner; 25% were with a spouse, 22% with a regular partner and 14% with a cohabiting partner. By contrast, women's relationships were most frequently with a spouse (36%); 25% were with a regular partner, and 20% each with a cohabiting and a casual partner.

Condom use was reported in a minority of partnerships but was more common outside than within marriage. Overall, 37% of men's partnerships and 29% of women's involved condom use at last intercourse. Regular partnerships were more likely than marital relationships to include such use (odds ratios, 3.1 for men and 2.5 for women). Use was even more likely in casual partnerships (5.1 for each gender); nevertheless, the prevalence of use in these partnerships was only 56% among men and 52% among women.

More than half of reported new partnerships occurred among respondents in their teens and early 20s, and the older respondents were, the less likely they were to have used a condom the first time they had sex with a new partner. The odds of this behavior were 70% lower in new partnerships among 35–44-year-old men than in those reported by male teenagers; for women's partnerships, the odds dropped by 80% from the youngest to the oldest age-group.

In the majority of new partnerships reported by both genders, the man was within five years of the woman's age, but this situation was more common among men than among women (73% vs. 63%). Women more often than men reported that the male was five or more years older than the female (25% vs. 20%). Same-age partners were more likely than couples in which the male was at least five years the female's senior to use a condom the first time they had intercourse (odds ratios, 2.2 for males and 1.7 for females); no difference was observed if the man was younger than the woman.

Men's and women's reports of where they had met recent new partners were largely similar. The most common places were pubs or restaurants, work, school and social events organized by friends. About three in five respondents of each gender reported that new partners lived in their city or town.

Men had first had sex with a new partner sooner than women had. Twenty-three percent of men's new partnerships had included sexual activity within the first 24 hours; in another 14%, the couple had had sex within one week after meeting. Among women's partnerships, 11% had included intercourse within 24 hours, and by one week, sexual activity had begun only in another 10%. Men who had had sex within 24 hours of meeting a new partner were more likely to have used a condom at that time than were men whose first sexual encounter with a new partner had occurred after a day or more.

The researchers comment that ambiguity in the wording of survey questions about when and where respondents first met their partners may have influenced some of the findings. On the other hand, they emphasize that the study improved on earlier work by using an analytic approach that permitted them to draw conclusions about the entire population of partnerships in the past year, rather than current or most recent ones. This approach, they maintain, contributes to a greater understanding of “who has sex with whom, and how partnership characteristics relate to condom use and thus [STD] risk.”

—D. Hollander

REFERENCE

1. Mercer CH et al., Who has sex with whom? characteristics of heterosexual partnerships reported in a national probability survey and implications for STI risk, International Journal of Epidemiology, 2008, doi:10.1093/ije/dyn216.