Geographic variation in sexual behaviour in Britain: implications for sexually transmitted disease epidemiology and sexual health promotion.
To explore geographical variation in sexual behaviour in Great Britain with reference to the prevalence of HIV infection. The National Survey of Sexual Attitudes and Lifestyles comprises a randomly selected, representative sample of almost 19,000 men and women aged 16-59 years living in Great Britain. The survey was carried out using a combination of face-to-face interview and self-completion questionnaires and a wide range of data was collected. In this study, data on numbers and sex of sexual partners, condom use, injecting drug use, perception of risk of AIDS and lifestyle change were analysed, and comparisons were made between the different geographical areas in Great Britain. In the last 5 years, men living in Inner London were more likely to have a male partner [odds ratio (OR), 5.6; 95% confidence interval (CI), 3.1-10.0] or to have had 10 or more female partners (OR, 2.4; 95% CI, 1.6-3.6) than men living in other parts of the country. Similar results were observed for women living in Inner London: OR for a female partner in the last 5 years was 4.1 (95% CI, 1.6-10.2) and for five or more male partners in the last 5 years was 2.1 (95% CI, 1.5-2.8). More complex, but less striking patterns of behaviour were seen in different parts of the country. Both men and women living in Inner London were more likely to recognize that they were at some risk of acquiring HIV and were also more likely to report a change in sexual lifestyle. These analyses highlight the difficulties inherent in extrapolating from sexual behaviour data gathered using purposive samples to the population as a whole. The results are consistent with the known epidemiology of HIV and sexually transmitted diseases in Britain. The data suggest that cases of HIV will continue to be concentrated in Inner London, but Londoners are particularly aware of their risk. Reported behaviour change in response to perception of risk of AIDS underlines the importance of effective health promotion.