The reported prevalence of risky sexual behavior is rising in Great Britain, according to an analysis comparing results of the 2000 and 1990 rounds of the National Survey of Sexual Attitudes and Lifestyles (Natsal).1 Both men and women in the more recent survey said that they had had a significantly larger number of lifetime heterosexual partners than their counterparts had reported a decade earlier; they also had increased odds of reporting recent anal intercourse or oral-genital contact. Overall, the consistency of condom use improved between surveys, but among men and women who had had multiple partners in the past year, the odds of inconsistent use were elevated in the later round.
Natsal is a probability sample survey of British residents aged 16-44. In 1990, when Natsal was first conducted, respondents participated in face-to-face interviews and completed self-administered questionnaires; in 2000, computer-assisted self-interview replaced the questionnaire component of the survey. A total of 13,765 respondents (6,000 men and 7,765 women) completed the first survey, and 11,161 respondents (4,762 men and 6,399 women) completed the more recent one. The data were weighted so that the sample was broadly representative of the British population.
In both surveys, the majority of respondents (roughly 70-75%) were aged 25-34; only 12% were teenagers. The proportion who were cohabiting was higher in the second survey than in the first (17% vs. 10%), while the proportion who were married was lower (42% vs. 52%).
On average, men in the later survey said they had had 12.7 lifetime sexual partners, and women reported having had 6.5. Eighteen percent of men and 24% of women reported no more than one lifetime partner; 60% and 46%, respectively, reported five or more. During the five years preceding the survey, men reportedly had had an average of 3.8 partners, while women had had 2.4. Fifty-one percent of men and 63% of women said they had had no partners or only one in the previous five years, but sizable proportions (21% and 12%, respectively) had had five or more. For both men and women, the mean number of partners during the last five years was highest among 16-24-year-olds and declined in each successive age-group.
Thirty-one percent of men and 21% of women in the second Natsal reported having had a new partner--overwhelmingly a partner of the opposite sex--in the past year. Of these, 57% of men and 43% of women said that the first time they had had intercourse with their most recent partner was within one month of their meeting.
Among all respondents who had had a sexual partner in the year before the 2000 survey, the researchers estimated that 15% of men and 9% of women had had concurrent relationships. Men and women who had had a heterosexual relationship during the previous year reportedly had had sex an average of 6-7 times in the four weeks before the survey.
One-quarter of men and one in five women interviewed for the second survey reported having used a condom at every act of intercourse in the past four weeks; the proportions were higher among those who had had two or more partners in the past year (33% of men and 24% of women) than among those who had had only one (21% and 17%, respectively). However, 15% of men and 10% of women had had multiple partners over the previous year and had not used condoms consistently during the month prior to the survey. Five percent of men and 3% of women considered themselves to be at high risk of contracting HIV.
The analysts compared data from the two rounds of Natsal by calculating age-adjusted odds ratios. Results of these analyses showed that for both men and women, the lifetime number of opposite-sex partners, number of such partners in the past five years and number of same-sex partners in the past five years increased significantly in the decade between surveys. Men and women in the later survey had elevated odds of ever having had a partner of the same sex, of having had a same-sex partner in the past five years and of recently having had concurrent partnerships (odds ratios, 1.4-3.4). While they were no more likely than their counterparts 10 years earlier to report recent vaginal intercourse, they had significantly higher odds of reporting oral-genital contact or anal intercourse (1.6-1.9). Men had higher odds in 2000 than in 1990 of saying that they had paid for sex in the past five years and that they had ever injected drugs (2.1 for each); women in 2000 had reduced odds of reporting injection-drug use in the past five years.
For both men and women, the odds of consistent condom use during vaginal or anal sex in the four weeks before the survey were significantly elevated in 2000 (odds ratio, 1.5 for men and 1.3 for women). However, the odds of both having had two or more partners in the past year and having used condoms inconsistently in the previous month were elevated (1.2 for men and 1.5 for women). Respondents to the second survey had higher odds than those participating in 1990 of considering themselves "quite a lot or greatly at risk of HIV" (1.8 for men and 1.5 for women).
The analysts acknowledge that some of the behavioral changes identified by the 2000 Natsal may reflect respondents' greater willingness to report behaviors because of societal changes and the use of computer-assisted self-interview. Still, they conclude that "despite raised public awareness of sexual health issues and the challenges of the global HIV epidemic, [the] results imply sustained population risk, which should signal a re-appraisal of the effectiveness of the programmes of the past decade and provide impetus for new approaches to, and investment in, public health interventions to improve sexual health."--D. Hollander
1. Johnson AM et al., Sexual behaviour in Britain: partnerships, practices, and HIV risk behaviours, Lancet, 2001, 358(9296):1835-1842.