Heterosexual behaviour and HIV risk in New Zealand: data from a national survey

Differences Between Landline and Mobile Phone Users in Sexual Behavior Research

This study investigated differences between the demographic characteristics, participation rates (i.e., agreeing to respond to questions about sexual behavior), and sexual behaviors of landline and mobile phone samples in Australia. A nationally representative sample of Australians aged 18 years and over was recruited via random digit dialing in December 2011 to collect data via computer-assisted telephone interviews. A total of 1012 people (370 men, 642 women) completed a landline interview and 1002 (524 men, 478 women) completed a mobile phone interview. Results revealed that telephone user status was significantly related to all demographic variables: gender, age, educational attainment, area of residence, country of birth, household composition, and current ongoing relationship status. In unadjusted analyses, telephone status was also associated with women's participation rates, participants' number of other-sex sexual partners in the previous year, and women's lifetime sexual experience. However, after controlling for significant demographic factors, telephone status was only independently related to women's participation rates. Post hoc analyses showed that significant, between-group differences for all other sexual behavior outcomes could be explained by demographic covariates. Results also suggested that telephone status may be associated with participation bias in research on sexual behavior. Taken together, these findings highlight the importance of sampling both landline and mobile phone users to improve the representativeness of sexual behavior data collected via telephone interviews.

HIV prevalence among men who have sex with men in New Zealand 1985–2009: 25 years of public health monitoring

Annual population-based estimates of the number of men who have sex with men (MSM) with diagnosed HIV infection (HIV prevalence pool), and the proportion of all MSM this represents (HIV prevalence), have been insufficiently described over the long term. We investigated the dynamic effects of ongoing HIV diagnoses, lower mortality due to treatment and growth in the MSM population over time on these two epidemic indicators using national HIV/AIDS surveillance data in New Zealand, 1985–2009. The diagnosed HIV prevalence pool rose 79% between 1989 and 1999, and 137% between 1999 and 2009. Estimates of diagnosed HIV prevalence as a proportion of MSM were 0.2% of MSM in 1985, and were between 1.5% and 5.0% of MSM by 2009. New Zealand continues to have a relatively low-prevalence HIV epidemic among MSM; however, the number of MSM living with diagnosed infection is growing rapidly 25 years after HIV testing was introduced.

Improving the health of sex workers in NSW: maintaining success

NSW has a diverse sex industry that is limited in its size by modest demand. There is no evidence that decriminalisation in 1995 increased the frequency of commercial sex in NSW. Though the largest sector, female brothels, is now mainly staffed by Asian women, condom use for vaginal and anal sex exceeds 99% and sexually transmissible infection rates are at historic lows. These gains are attributable to the long-term support of the NSW Department of Health in collaboration with the community-based Sex Workers Outreach Project and sexual health services, facilitated by the removal of criminal sanctions without the expense and access barriers of licensing systems.

Multiple aspects of sexual orientation: prevalence and sociodemographic correlates in a New Zealand national survey

Sexual orientation consists of multiple components. This study investigated both sexual identity and same-sex sexual behavior. Data came from the New Zealand Mental Health Survey, a nationally representative community sample of New Zealanders aged 16 years or older, interviewed face-to-face (N = 12,992, 48% male). The response rate was 73.3%. Self-reported sexual identity was 98.0% heterosexual, 0.6% bisexual, 0.8% homosexual, 0.3% "Something else," and 0.1% "Not sure." Same-sex sexual behavior with a partner was more common: 3.2% reported same-sex sexual experience only and 1.9% reported both experience and a relationship. For analysis of childhood and lifecourse, five sexuality groups were investigated: homosexual, bisexual, and heterosexual divided into those with no same-sex sexual experience, experience only, and experience and relationship. The non-exclusively heterosexual groups were more likely to have experienced adverse events in childhood. Educational achievement and current equivalized household income did not differ systematically across the sexuality groups. Only 9.4% of the exclusively heterosexual lived alone, compared with 16.7% of bisexuals and 19.0% of homosexuals. Heterosexuals were more likely than bisexuals or homosexuals to have ever married or had biological children, with differences more marked for males than for females. Heterosexuals with no same-sex sexual experience were more likely to be currently married than the other two heterosexual groups. Restricting comparisons to heterosexual, bisexual, and homosexual identification ignores the diversity within heterosexuals. Differences between the bisexual and homosexual groups were small compared with the differences between these groups and the exclusively heterosexual group, except for sex (80.8% of bisexuals were female).

Longitudinal study of self-reported sexually transmitted infection incidence by gender and age up to age thirty-two years

OBJECTIVES

To examine how incidence of self-reported sexually transmitted infections (STIs) varies by gender and age, and the factors that influence this.

METHODS

A longitudinal study of a cohort born in Dunedin, New Zealand in 1972/1973. They were questioned about STIs and sexual behavior at age 21, 26, and 32 years (1993-2005). Incidence rates were calculated over 3 age periods and compared using Poisson regression.

RESULTS

Of the 1037 members of the original cohort, 92% or more of survivors completed the computer questionnaire at each age. Incidence rates of STIs from first coitus to age 21, age 21 to 26, and age 26 to 32, were 2.0, 3.2, and 2.0 per 100 person-years, respectively for men and 4.4, 3.0, and 1.4 per 100 person-years, respectively for women. After adjustment for sexual behavior, rates for men were elevated from age 21 to 26 compared with first coitus to 21 years of age [incidence rate ratio (IRR) = 1.9, 95% confidence interval (CI) 1.3 to 2.8), but not from age 26 to 32 (IRR = 1.1, 95% CI 0.70-1.9). For women, adjusted rates decreased with age; from 21 to 26 compared with first coitus to 21 (IRR = 0.79, 95% CI 0.56-1.1) and further from 26 to 32 (IRR = 0.39, 95% CI 0.27-0.57).

CONCLUSIONS

These unique data, comprising repeated assessment of reported behaviors and STIs in the same population, show that the period before age 21 is a time of special risk for STIs for women and of lower risk for men. The low risk among women aged 26 to 32 years after adjustment for sexual behavior warrants further investigation.

Sex in Australia: Safer sex and condom use among a representative sample of adults

OBJECTIVE

To provide reliable estimates of the frequency of condom use and correlates of condom use among Australian adults.

METHODS

Computer-assisted telephone interviews were completed by a representative sample of 10,173 men and 9,134 women aged 16-59 years. The response rate was 73.1% (69.4% men, 77.6% women).

RESULTS

Although the majority of respondents had used a condom at some time in their lives, fewer than half of the respondents who were sexually active in the year before being interviewed had used a condom in the past year. Condom use in the past year was associated with youth, greater education, residence in major cities, lower incomes, white-collar occupations, being a former smoker, and having more sexual partners in the past year. In the six months prior to interview, 7.1% of respondents always used condoms with regular cohabiting partners, 22.5% always used condoms with regular non-cohabiting partners, and 41.4% always used condoms with casual partners. Approximately 20% of respondents used a condom the last time they had vaginal intercourse, and one in eight of these condoms were put on after genital contact. Condom use during the most recent sexual encounter was associated with youth, living in a major city, having a lower income, having sex with a casual partner, and not using another form of contraception.

CONCLUSION

As in other studies, condom use was strongly associated with partner type and use of other contraception.

IMPLICATIONS

People with multiple sexual partners need to be aware that non-barrier methods of contraception (and condoms applied late) do not protect against sexually transmitted infections.

Sex in Australia: Injecting and sexual risk behaviour in a representative sample of adults

OBJECTIVE

Some blood-borne and sexually transmissible agents may be spread by using non-sterile injecting equipment and by unprotected sexual intercourse. The objective of this study was to describe the prevalence of these risk factors in the general population of Australia.

METHODS

Computer-assisted telephone interviews were completed by a representative sample of 10,173 men and 9,134 women aged 16-59 years. The overall response rate was 73.1% (69.4% men, 77.6% women).

RESULTS

3% of respondents had ever injected non-prescription drugs; men were more likely than women to have done so. Predictors of injecting in men and women included being aged 20-29, homosexual or bisexual identity, and lower levels of education and income. Injecting was not more common in cities than elsewhere. Among people who had injected in the past year, 12.4% had shared needles and 43.0% had shared other paraphernalia. Sharing was significantly related to lower income. Unprotected sex with casual partners was more common in heterosexual activity than in male homosexual activity. Among heterosexually active respondents, 3.3% reported unprotected vaginal sex with casual partners (59% of those with such partners) and among homosexually active males 2.1% reported unprotected anal sex with casual partners (12% of those with such partners). Predictors of unprotected sex included indices of lower socio-economic status.

CONCLUSION

Sexual and injecting risks are reported by substantial minorities of the Australian population and are associated with indices of lower socio-economic status and bisexual identity. Programs are needed to address vulnerabilities to these infections.

Sex in Australia: The rationale and methods of the Australian Study of Health and Relationships

OBJECTIVE

To describe the methods and process of the Australian Study of Health and Relationships.

METHODS

A computer-assisted telephone interview was developed and applied to a stratified sample of the Australian population. After initially weighting to reflect the study design, the sample was further weighted to reflect the location, age and sex distribution of the 2001 Census.

RESULTS

Interviews were completed with 10,173 men and 9,134 women aged 16-59 years from all states and Territories. The overall response rate was 73.1% (69.4% among men and 77.6% among women). After accounting for the survey design and weighting to the 2001 Census, the sample appears broadly representative of the Australian population.

CONCLUSION

The combination of methods and design in the Australian Study of Health and Relationships, coupled with the high response rate, strongly suggests that the results of the study are robust and broadly representative of the Australian population.

Sex in Australia: Reflections and recommendations for future research

OBJECTIVE

To review the content, method and process of the Australian Study of Health and Relationships (ASHR).

RESULTS

ASHR achieved a large sample, a high response rate and documented the sexual life histories and current sexual health-related knowledge, attitudes and practices of the Australian population aged 16-59. Its cross-sectional nature limited our ability to partition observed variation between age and time despite clear evidence of both age-related and cohort-related changes in sexual practice. Similarly, its reliance on a sample of individuals reporting on their sexual experiences rather than a sample of sexual relationships or encounters and their participants limits our ability to understand the dynamics of those relationships and encounters. Finally, our understanding of sexuality in Australia could have been improved through qualitative studies with a subsample of ASHR participants.

CONCLUSION

ASHR represents a significant contribution to our understanding of sexual health-related knowledge, attitudes and practices in Australia.

Sex in Australia: homosexual experience and recent homosexual encounters

OBJECTIVE

To describe the prevalence and features of homosexual experience and recent homosexual encounters among a representative sample of Australian adults.

METHODS

Computer-assisted telephone interviews were completed by a representative sample of 10,173 men and 9,134 women aged 16-59 years from all States and Territories. The overall response rate was 73.1% (69.4% among men and 77.6% among women).

RESULTS

Overall, 8.6% of women and 5.9% of men reported some homosexual sexual experience in their lives (p<0.001); these figures fell to 5.7% and 5.0% respectively (p=0.106) when non-genital sexual experience was excluded. 1.9% of men and 1.5% of women reported homosexual experience in the past year. Men who reported homosexual experience reported more same-sex partners than did women (means 31.6 and 3.2, p<0.001), and men and women who identified as homosexual or bisexual reported more sexual partners in total than those who identified as heterosexual. Respondents reporting homosexual experience were significantly more likely to be from an English-speaking background, have higher levels of education, live in a major city, and report a white-collar or managerial/professional occupation. Women who reported homosexual experience were less likely to have a middle or high income. In the most recent homosexual encounter, genital touching was the most commonly reported practice, and oral sex was reported much more frequently than in heterosexual encounters.

CONCLUSION

Homosexually and bisexually identified men and women had higher total numbers of partners than heterosexuals. Improved societal attitudes towards homosexuality are likely to lead to further increases in estimates of the prevalence of homosexual experience in the community.

Sex in Australia: experiences of commercial sex in a representative sample of adults

OBJECTIVE

To describe the characteristics of Australian adults' experience of commercial sex.

METHOD

Telephone interviews were completed by a representative sample of 10,173 men and 9,134 women aged 16-59 years (response rate 73.1%; 69.4% men, 77.6% women). Respondents were asked about their experiences both as clients and as sex workers. Socio-demographic and health factors associated with experience of commercial sex were explored for men.

RESULTS

Almost one in six Australian men (15.6%) have ever paid for sex; 1.9% had done so in the past year. Of men who had ever paid for sex, 97% had paid for sex with a woman and 3% for sex with a man. Very few women (0.1%) had ever paid for sex. Twice as many men (0.9%) as women (0.5%) had ever been paid for sex; two-thirds of these men (0.6%) were paid by other men. Condom use during vaginal sex was highest in parlours and brothels and with escorts, and lowest for street sex work. Two-thirds of women who had ever been paid for sex had done so only overseas. One in 10 men who had paid for sex had only done so overseas. Men who had paid for sex were more likely than other men to smoke, to drink more alcohol, to have had a sexually transmitted infection or been tested for HIV, to have more sexual partners, to have first had vaginal intercourse before 16, and to have had heterosexual anal intercourse.

CONCLUSION

Sex work overseas, where condom use may not be common, represents a potential source of HIV or sexually transmitted infection.

Same-sex attraction in a birth cohort: prevalence and persistence in early adulthood

There is a continuing debate about the importance of social versus biological factors in the expression of same-sex attraction. Investigation of prevalence, continuities, and changes over time among young adults growing up in a country with a relatively accepting climate to homosexuality is likely to illuminate this debate. Analyses were therefore undertaken of self-reported same-sex attraction at age 21 and 26, in a cohort of about 1000 people born in 1972/3 in one New Zealand city. Participants were also asked about same-sex behaviour and attitudes to same-sex relationships. By age 26, 10.7% of men and 24.5% of women reported being attracted to their own sex at some time. This dropped to 5.6% of men and 16.4% of women who reported some current same-sex attraction. Current attraction predominantly to their own sex or equally to both sexes (major attraction) was reported by 1.6% of men and 2.1% of women. Occasional same-sex attraction, but not major attraction, was more common among the most educated. Between age 21 and 26, slightly more men moved away from an exclusive heterosexual attraction (1.9% of all men) than moved towards it (1.0%), while for women, many more moved away (9.5%) than towards (1.3%) exclusive heterosexual attraction. These findings show that much same-sex attraction is not exclusive and is unstable in early adulthood, especially among women. The proportion of women reporting some same-sex attraction in New Zealand is high compared both to men, and to women in the UK and US. These observations, along with the variation with education, are consistent with a large role for the social environment in the acknowledgement of same-sex attraction. The smaller group with major same-sex attraction, which changed less over time, and did not differ by education, is consistent with a basic biological dimension to sexual attraction. Overall these findings argue against any single explanation for homosexual attraction.

Prostitution and the sex discrepancy in reported number of sexual partners

One of the most reliable and perplexing findings from surveys of sexual behavior is that men report substantially more sexual partners than women do. We use data from national sex surveys and studies of prostitutes and their clients in the United States to examine sampling bias as an explanation for this disparity. We find that prostitute women are underrepresented in the national surveys. Once their undersampling and very high numbers of sexual partners are factored in, the discrepancy disappears. Prostitution's role in the discrepancy is not readily apparent because men are reluctant to acknowledge that their reported partners include prostitutes.

Sexual practice and understandings of safe sex: assessing change among 18- to 19-year-old Australian tertiary students, 1988 to 1994

From 1988 to 1994, first-year students in a large introductory class at Macquarie University completed a questionnaire regarding sexual practice, knowledge of transmission of human immunodeficiency virus (HIV) and understandings of safe sex. Data from 18- and 19-year-old students were analysed to examine changes over time among recent school leavers. Approximately 58 per cent were sexually experienced, young men were more experienced than young women, and both had more experience with regular than with casual partners. The number of partners did not vary over the years, most respondents having had one or two partners. Changes over time were found with respect to condom use, particularly with regular partners. The percentage using condoms "always' with casual partners was greater, having increased to around 60 per cent. Accuracy of knowledge relating to safety of sexual practices with casual and with regular partners increased over time, particularly with respect to regular partners. While both accuracy of knowledge and safety of practice increased with time, there was no relationship between these two variables in any one year. The findings suggest that there has been normative change with regard to condom use and that this has occurred within a reasonably static and unchanging set of sexual practices. Sex education appears to be one of the factors contributing to this change.