Catherine H Mercer

Sexual behaviour in Britain: partnerships, practices, and HIV risk behaviours

BACKGROUNDnSexual behaviour is a major determinant of sexual and reproductive health. We did a National Survey of Sexual Attitudes and Lifestyles (Natsal 2000) in 1999-2001 to provide population estimates of behaviour patterns and to compare them with estimates from 1990-91 (Natsal 1990).nnnMETHODSnWe did a probability sample survey of men and women aged 16-44 years who were resident in Britain, using computer-assisted interviews. Results were compared with data from respondents in Natsal 1990.nnnFINDINGSnWe interviewed 11161 respondents (4762 men, 6399 women). Patterns of heterosexual and homosexual partnership varied substantially by age, residence in Greater London, and marital status. In the past 5 years, mean numbers of heterosexual partners were 3.8 (SD 8.2) for men, and 2.4 (SD 4.6) for women; 2.6% (95% CI 2.2-3.1) of both men and women reported homosexual partnerships; and 4.3% (95% CI 3.7-5.0) of men reported paying for sex. In the past year, mean number of new partners varied from 2.04 (SD 8.4) for single men aged 25-34 years to 0.05 (SD 0.3) for married women aged 35-44 years. Prevalence of many reported behaviours had risen compared with data from Natsal 1990. Benefits of greater condom use were offset by increases in reported partners. Changes between surveys were generally greater for women than men and for respondents outside London.nnnINTERPRETATIONnOur study provides updated estimates of sexual behaviour patterns. The increased reporting of risky sexual behaviours is consistent with changing cohabitation patterns and rising incidence of sexually transmitted infections. Observed differences between Natsal 1990 and Natsal 2000 are likely to result from a combination of true change and greater willingness to report sensitive behaviours in Natsal 2000 due to improved survey methodology and more tolerant social attitudes.

Sexual behaviour in Britain: early heterosexual experience.

BACKGROUNDnRelatively high rates of teenage conception and sexually transmitted infection among young people in Britain have focused attention on early sexual behaviour and its determinants. We report the results of the second National Survey of Sexual Attitudes and Lifestyles (Natsal 2000).nnnMETHODSnWe did a probability sample survey between 1999 and 2001, of men and women aged 16-44 years in Britain. Participants were interviewed using a combination of computer-assisted face-to-face and self-completion questionnaires, and asked questions regarding first heterosexual intercourse, communication about sex, pregnancy, and sexually transmitted infections (STIs).nnnFINDINGSnWe recruited 11161 men and women to the survey (4762 men, 6399 women). The proportion of those aged 16-19 years at interview reporting first heterosexual intercourse at younger than 16 years was 30% for men and 26% for women; median age was 16 years. The proportion of women reporting first intercourse before 16 years increased up to, but not after, the mid-1990s. There has been a sustained increase in condom use and a decline in the proportion of men and women reporting no contraceptive use at first intercourse with decreasing age at interview. Among 16-24 year olds, non-use of contraception increased with declining age at first intercourse; reported by 18% of men and 22% of women aged 13-14 years at occurrence. Early age at first intercourse was significantly associated with pregnancy under 18 years, but not with occurrence of STIs. Low educational attainment was associated with motherhood before 18 years, but not abortion.nnnINTERPRETATIONnThe increase in the proportion of women reporting first intercourse before age 16 years does not appear to have continued throughout the past decade. Only a small minority of teenagers have unprotected first intercourse, and early motherhood is more strongly associated with educational level than with family background. Factors most strongly associated with risk behaviour and adverse outcomes have considerable potential for preventive intervention.

Sexual behaviour in Britain: reported sexually transmitted infections and prevalent genital Chlamydia trachomatis infection

BACKGROUNDnStudies of the epidemiology of sexually transmitted infections (STI) are largely based on surveillance data. As part of a national survey of sexual attitudes and lifestyles (Natsal 2000) in Britain, we estimated the frequency of self-reported STIs, and the prevalence of urinary Chlamydia trachomatis infection.nnnMETHODSnWe did a stratified probability sample survey of 11161 men and women aged 16-44 years in Britain. Computer assisted self-interviews contained items on the nature and timing of previously diagnosed STIs. Half of all sexually experienced respondents aged 18-44 years were invited to provide a urine sample for ligase chain reaction testing for C trachomatis infection.nnnFINDINGSn10.8% of men and 12.6% of women reported ever having an STI, 3.6% of men and 4.1% of women reported ever being diagnosed with genital warts, and 1.4% of men and 3.1% of women reported previous infection with C trachomatis. 76% of men and 57% of women ever diagnosed with an STI had been to a GUM clinic. C trachomatis was found in 2.2% (95% CI 1.5-3.2) of men and 1.5% (95% CI 1.11-2.14) of women with age-specific prevalence being highest among men aged 25-34 (3.1%) and women aged 16-24 years (3.0%). Non-married status, age, and reporting partner concurrency or two or more sexual partners in the past year were independently associated with infection with C trachomatis.nnnINTERPRETATIONnWe show substantial heterogeneity in distribution of reported STIs, and the demographic and behavioural determinants of prevalent genital chlamydial infection. The results have potentially wide application for proposed chlamydia screening programmes which, given the demonstrated prevalence, must now proactively seek to involve men.

Reported Sexually Transmitted Disease Clinic Attendance and Sexually Transmitted Infections in Britain: Prevalence, Risk Factors, and Proportionate Population Burden

BACKGROUNDnWe examined attendance at sexually transmitted disease (STD) clinics and the prevalence, distribution, and associated demographic and behavioral factors of self-reported sexually transmitted infections (STIs) in a population survey of sexual attitudes and lifestyles.nnnMETHODSnWe analyzed data from stratified probability sample surveys obtained through the British National Surveys of Sexual Attitudes and Lifestyles (Natsal), which was undertaken in 1990 (n=13,765) and 2000 (n=11,161) among men and women aged 16-44 years. National STD surveillance data for 1999 were used to determine disease- and risk factor-specific proportionate population burden (PPB).nnnRESULTSnBetween 1990 and 2000, the number of subjects who reported having attended an STD clinic during the past 5 years increased from 4.3% to 7.6% among men and from 3.3% to 6.6% among women. In 2000, 3.0% of men and 4.0% of women reported having received a diagnosis of an STI during the past 5 years; 77.6% of men and 60.3% of women with an STI had attended an STD clinic. Reported STI acquisition was independently associated with age, increasing numbers of sex partners, male homosexual partners, and partners from abroad (for women only). Of all reported STIs during the past 5 years (PPB, 10.2%), 10.2% were reported by the 2.9% of men who reported having had homosexual partners during the past 5 years. Of all reported STIs in the past 5 years (PPB, 41.6%), 41.6% were reported by the 4.0% of women who reported having > or =10 sex partners during that time. Analysis of national STI surveillance data showed that the PPB for new episodes of Chlamydia trachomatis diagnosed among homosexual men was 2.8%, that for gonorrhea was 17.4%, and that for syphilis was 32.1%.nnnCONCLUSIONSnNumbers and types of sexual partnerships remain the dominant individual and population risk factors for STI acquisition. Combined population behavior and surveillance data demonstrate the high PPB for STIs attributable to key risk factors. PPB may be a useful indicator of epidemic phase and may help target resources and guide prevention strategies.

Who pays for sex? An analysis of the increasing prevalence of female commercial sex contacts among men in Britain

Background: In the United Kingdom the incidence of sexually transmitted infections (STI) and risky sexual behaviours is increasing. The role of commercial sex in this trend is poorly understood. Little is known about the men who pay for sex. We examined the epidemiology of female commercial sex contacts reported by men in 1990 and 2000. Methods: National probability sample surveys of sexual attitudes and lifestyles (Natsal) of men aged 16–44 resident in Britain in 1990 (nu200a=u200a6000) and 2000 (nu200a=u200a4762). Results: The proportion of men who reported paying women for sex in the previous 5 years increased from 2.0% (95% CI 1.6 to 2.5) in 1990 to 4.2% in 2000 (95% CI 3.6 to 4.9). In both surveys, paying for sex was more frequent in men aged between 25 years and 34 years, who were never or previously married, and who lived in London. There was no association with ethnicity, social class, homosexual contact, or injecting drug use. Men who paid for sex were more likely to report 10 or more sexual partners in the previous 5 years; only a minority of their lifetime sexual partners (19.3%) were commercial. They were more likely to meet partners abroad and to report previous STI. Only 15% reported having had an HIV test. Conclusion: The proportion of men who reported paying for heterosexual sex has increased, and these men have multiple commercial and non-commercial partners. Their higher rates of STI and low level of HIV testing suggest the need for prevention interventions for clients as well as sex workers.

Sex partner acquisition while overseas: results from a British national probability survey

Background: Over the past 20 years, there has been a huge increase in the number of overseas trips made by UK residents. Although a number of studies have examined the frequency of overseas partner acquisition, they have used convenience samples and thus are not generalisable to the British general population. Methods: A national probability sample survey was carried out in 1999–2001 of 12 110 men and women aged 16–44 years resident in Britain. Sociodemographic, health-related, travel, sexual behaviour and attitudinal data were collected by computer-assisted interviewing. The main outcomes were the proportion of British residents who reported new sexual partners overseas in the past 5 years, the country of origin of these new sex partners, and the association between reporting a new partner while overseas with a range of demographic, behavioural and attitudinal variables. Results: 13.9% of men and 7.1% of women reported having new sexual partner(s) while overseas in the past 5 years. Among respondents who were aged 16–24 and never married, the proportions were significantly higher (23.0% of men and 17.0% of women). Half of those with new sex partners overseas reported their partner’s origin as the UK, and over a third as another European country. In addition to age and marital status, reporting new partners overseas was associated with a higher number of partners, paying for sex (among men), reporting a diagnosis of sexually transmitted infection, and HIV testing. Adjustment for sociodemographic factors attenuated the magnitude of, but did not remove, these associations. Conclusions: A substantial minority of young, unmarried people form new sexual partnerships abroad, but these are typically with residents from the UK or other European countries. Those who have new partners abroad are likely to have higher-risk sexual lifestyles more generally, and to be at higher risk of sexually transmitted infections. Greater attention should be paid to sexual health promotion for travellers abroad, especially young travellers, emphasising the risks of new sexual relationships with compatriots as well as those from other countries in terms of STI/HIV acquisition and onwards transmission.

Alcohol misuse, sexual risk behaviour and adverse sexual health outcomes: evidence from Britain's national probability sexual behaviour surveys.

BACKGROUNDnEvidence for relationships between alcohol misuse, sexual risk behaviour and adverse sexual health outcomes exists from both population-level data and studies undertaken in specific groups. We examine changes in these associations using representative data from two consecutive surveys.nnnMETHODSnProbability surveys conducted in 1990/91 and again in 2000/01 involving interviews with British residents aged 16-44.nnnRESULTSnThe proportion reporting being drunk as their main reason for first heterosexual intercourse increased from 2.5% among those born in 1946-49 to 6.4% of those born in 1980-84. These respondents were more likely to report intercourse before 16, that sex had occurred too soon, and contraception non-use. Usual alcohol consumption in excess of recommended limits (heavy drinkers) was more common among those reporting larger partner numbers and unprotected sex with 2+ partners/past year but not with STD clinic attendance/diagnosis. Male heavy drinkers were more likely to report sexual function problems and female heavy drinkers using emergency contraception. The magnitude of these relationships did not significantly increase between 1990/91 and 2000/01.nnnCONCLUSIONnIn Britain, sexual risk behaviours and some adverse sexual health outcomes continue to be associated with excess alcohol consumption. These findings support addressing the link between alcohol misuse and sexual health in health services and through broader health promotion.

Who is being tested by the English National Chlamydia Screening Programme? A comparison with national probability survey data.

Objectives We compare data collected by Englands National Chlamydia Screening Programme (NCSP) with national probability survey data to examine demographic and behavioural differences that may be important in understanding who the NCSP is reaching and interpreting chlamydia positivity. Methods Data for 538u2008119 men and women aged 16–24u2005years who were screened in 2008 and data collected from 2180 interviewees in Britains second National Survey of Sexual Attitudes and Lifestyles 1999–2001 (Natsal-2), of whom 644 were tested for chlamydia, were compared using the χ2 statistic and logistic regression. Results Compared with Natsal-2, the NCSP tested more women (67% vs 49%). NCSP participants were more likely to be younger: 29% were 16–17u2005years versus 16% of men and 15% of women in Natsal-2; from ethnic minority groups: 17% of men and 14% of women versus 8% and 6%, respectively, in Natsal-2; not to have used condoms at last sex: 66% of men and 68% of women versus 48% and 63%, respectively, in Natsal-2: and more likely to report two or more partners in the last year: 62% of men and 47% of women versus 47% and 30%, respectively, in Natsal-2. In multivariate analyses, higher AOR of chlamydia positivity were found for those reporting non-use of condoms and for those reporting multiple partners in both the NCSP and Natsal-2. Conclusions The NCSP is testing young people at increased risk of chlamydia. The impact of this testing bias on the effectiveness of the programme should be evaluated.

Who uses condoms with whom? Evidence from national probability sample surveys

Objectives: To explore the changing pattern of condom use from 1990 to 2000; to identify sociodemographic and behavioural factors associated with condom use; and reasons for condom use in 2000. Methods: Large probability sample surveys administered among those resident in Britain aged 16–44 (nu200a=u200a13 765 in 1990, nu200a=u200a11 161 in 2000). Face to face interviews with self completion components collected sociodemographic, behavioural, and attitudinal data. Results: Condom use in the past year among sexually active 16–24 year old men increased from 61.0% in 1990 to 82.1% in 2000 (p<0.0001), and from 42.0% to 63.2% (p<0.0001) among women of the same age, with smaller increases among older age groups. Among individuals reporting at least two partners in the previous 4 week period, approximately two thirds reported inconsistent or no condom use (63.1% (95% CI 55.9% to 69.8%) of the men and 68.5% (95% CI 57.6% to 77.7%) of the women). Conclusions: Rates of condom use increased substantially between 1990 and 2000, particularly among young people. However, inconsistent condom use by individuals with high rates of partner acquisition may contribute significantly to the recent resurgence in STIs. This group is an important target for intensive and specific sexual health interventions.

Chlamydia trachomatis testing in the second British national survey of sexual attitudes and lifestyles: respondent uptake and treatment outcomes.

Background: Noninvasive molecular tests for bacterial sexually transmitted infections (STIs) provide new opportunities for testing in nonclinical settings. Little information is available on the outcomes when applied to asymptomatic sex survey participants. Objective: The objective of this study was to examine patient treatment preferences and partner notification outcomes among Chlamydia trachomatis-positive cases identified in the 2000 national survey of sexual attitudes and lifestyles (Natsal 2000), and factors associated with providing a urine sample. Methods: The authors conducted a stratified probability sample survey of 11,161 men and women aged 16 to 44 years residing in Britain using computer-assisted self-interviews. Urine testing was performed for C. trachomatis offered to a random half of sexually active respondents aged 18 to 44 using ligase chain reaction. Notification, treatment, and follow up of ligase chain reaction-positive respondents were undertaken. Results: A total of 5105 respondents were invited to provide a urine sample. A total of 3628 (71%) agreed and 3608 samples were successfully tested. Willingness to provide a urine sample was significantly higher among those reporting previous homosexual experience, heterosexual anal sex, and STI diagnosis. Seventy-three respondents (31 men and 42 women) were diagnosed with genital chlamydial infection. Sixty-five (89%) responded to notification of their infection and were recommended for treatment and partner notification. Fifty (77%) respondents preferred to be seen by their general practitioner and 15 (23%) by their local genitourinary medicine clinic. Although physician feedback on treatment and partner notification outcomes was obtained for only half (n = 34) of respondents, follow-up respondent interviews confirmed that a total of 49 (75%) respondents underwent this process. Interpretation: In this community-based survey, the rate of provision of urine samples was high, and those who provided samples were found to be at somewhat greater risk of infection on average. This was accounted for in estimating population chlamydia prevalence. The authors found that treatment and partner notification of newly diagnosed infections can be successfully achieved in STI prevalence studies.