Introduction

Group sex among Australian gay men has been associated with unprotected anal intercourse with casual partners (UAIC) and, specifically, with UAIC that is not seroconcordant (i.e., between casual partners with differing HIV serostatus or where one or both partners’ HIV serostatus was unknown) [1]. Also, group sex is a key indicator of participation in highly sexually active ‘scenes’ which have been associated with sexual risk behaviours and illicit drug use among gay men [2, 3].

While group sex in itself may not necessarily be ‘unsafe’ depending on the specific sexual practices involved, increased risk of sexually transmissible infections (STI) has been associated with group sex. Group sex is one key indicator of participation in sexually adventurous subcultures which have previously been associated with HIV seroconversion [4] and STI transmission [5] among gay men and have been identified as a key factor for sexual risk behaviour among gay men [6–9]. Group sex also necessarily involves multiple concurrent partners, and the men who engage in this activity are therefore at increased risk of STI in general and, specifically, of HIV infection and transmission where it involves UAIC [10].

Sowell et al. [11] found that men who engaged in group sex devalued the possibility of HIV risk, in favour of an emphasis on sexual pleasure and excitement. This accords with the concept of ‘intensive sex partying’ where considerations of pleasure, and its intensification, may sometimes be given greater value than concerns about HIV, or other risk [12]. In these contexts, party drugs are often used to enhance the sexual experience and are associated with an increased likelihood to engage in UAIC [13].

In consideration of the fact that gay men who engage in group sex are probably at high risk of infection with and transmission of HIV and other STI, the Australian behavioural surveillance system’s Gay Community Periodic Surveys (GCPS), which commenced in 2006, started collecting data about group sex in 2007 [14, 15]. In this paper, we investigated the extent of sexual risk taking among gay men who engaged in group sex. We sought to document the prevalence and frequency of group sex and to examine factors associated with participation in group sex within this well-established community survey of risk behaviour among Australian gay men.

Methods

Participants

Participants were from the ongoing Australian GCPS of gay men in 2008 in Sydney, Melbourne and Brisbane. Participants were recruited from gay community venues, events and clinics. To be eligible, participants had to live in each of the cities or to regularly participate in that city’s local gay community; regular participation was self-defined. They also had to either identify as homosexual or bisexual or have had any sexual contact (any of oral or anal intercourse or other penetrative practices, or mutual masturbation) with another man in the previous 5 years. Approximately 78% of eligible men who were asked to participate completed a questionnaire. In each state capital, the survey is conducted over one-week period to coincide with a major gay community festival, but is also conducted on a second occasion 6 months later each year in Sydney. To ensure comparability across the samples, the Sydney sample included only those men recruited during the first round of the survey in each year. In 2008, 5,432 men were recruited.

Questionnaire

Participants completed a brief self-administered paper and pencil questionnaire on a broad range of topics including: demographics, sexual self-identity, HIV testing, sexual relationships and sexual practices with regular and casual partners. Questions about group sex experience were introduced in 2007 [14].

Outcome Variables

Men were asked several questions about sexual behaviour: whether they had sex with casual or regular male partners in the previous 6 months; group sex; oral and anal intercourse, separately for the insertive and receptive positions, with these partners; and whether they used condoms during each of insertive and receptive anal intercourse. HIV serostatus of casual partners was not assessed. A single measure of any unprotected anal intercourse with casual partners was created from these separate items to assess sexual risk behaviour.

Data Analyses

There was no difference between 2007 and 2008 in terms of likelihood to engage in group sex so we have included the most recent year in our analyses. The samples from all three states were combined and only men who reported sex with casual partners in the previous 6 months were included in analysis. Among men who did not report sex with casual partners, an additional 114 men indicated they had engaged in group sex that involved their regular partner—these men most likely attended group sex events with regular partners only and restricted their actual sexual behaviour to just their regular partners. Sexual behaviour with regular partners has been found to be very different to sexual behaviour with casual partners, particularly on the key indicators of HIV risk, and as our analyses concern sex partying that mostly occurs in the context of casual sex, respondents who did not report sex with casual partners have not been included in these analyses. We tested for associations with having engaged in group sex with casual partners, both ever in previous 6 months and at least monthly during that time. For univariate analyses, categorical variables were analysed using Pearson’s chi-square test with Type I error of 5%. To estimate statistical associations, we used logistic regression models and presented unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (CI).

Results

There were 5,432 completed survey questionnaires in Sydney, Melbourne or Brisbane in 2008 (Table 1). When asked about sexual contacts during the previous 6 months, 3,707 men (68.2%) reported having sex with casual partners. Men who reported no sexual contact with casual partners in the preceding 6 months were excluded from further analysis. Among the 3,707 men who reported sex with casual partners, the majority (59.9%) also reported having had sex with a regular partner in the previous 6 months.

Table 1 Univariate associations with group sex during previous 6 months, 2008
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Men included here were recruited through gay community events (56.7%), social venues (23.7%), sex-on-premises venues (13.5%) and clinics (6.2%). Consistent with the recruitment strategies, most men identified as gay or homosexual (88.5%) and had extensive gay community social networks: 46.3% indicated that most or all of their friends were gay men and 41.9% spent a lot of their free time with gay men. Nearly three quarters (72.0%) were of an Anglo-Australian origin. One-third (32.4%) were in managerial or professional occupations and half (51.3%) had some university education. Mean age was 36.4 years.

Among the men reporting sex with casual partners during the previous 6 months, 44.0% reported having engaged in group sex with any of those partners, although mostly they did so infrequently (Table 1). Also among men reporting sex with casual partners, nearly one in five indicated that their regular partners had participated in some of these group sex encounters.

The majority of those who had engaged in group sex reported doing so infrequently: 443 men (12.0%) reported engaging in group sex at least monthly; 238 men (6.4%) about once every 6 months, and 949 men (25.6%) just once or a few times only. Respondents were also asked whether they had attended private sex parties in the previous 6 months: 604 (16.3%) indicated they had attended sex parties.

In the univariate analyses, men who engaged in group sex were somewhat older, had slightly lower education levels, and were more likely to report having tested HIV-positive than men who did not engage in group sex (Table 1). Unsurprisingly, engaging in group sex was associated with being recruited at sex venues and having a greater number of partners in the previous 6 months. Brisbane men were slightly less likely to have engaged in group sex than men from other cities in univariate analysis. Men who engaged in UAI both with their regular partners and with casual partners were more likely to have engaged in group sex, and to have done so more frequently, than those who did not engage in UAI. Those who did not engage in anal intercourse at all were particularly less likely to have engaged in group sex. These associations were generally true regardless of HIV serostatus. Nonetheless, HIV-positive men were more likely to report UAIC in general: 55.6% of HIV-positive men reported engaging in UAIC in the previous 6 months, compared with 27.7% of HIV-negative men and 27.4% of those whose HIV status was unknown. These differences were more pronounced among men who engaged in group sex (Table 2).

Table 2 HIV serostatus, UAIC and group sex during previous 6 months, 2008, n(%)
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Respondents were also asked about use of illicit drugs during the previous 6 months. Those who did not report engaging in group sex were less likely to report using drugs in general (Table 3). This was also true for each type of drug and those who used drugs more often were even more likely to report group sex. Over a quarter (28.6%) of the men who engaged in group sex at least monthly, and one in six (18.5%) of those who engaged in group sex less frequently, reported using ‘party drugs’ specifically to enhance their sexual performance and pleasure, compared to 4.4% of those who did not engage in group sex at all (P < 0.001).

Table 3 Drug use and group sex during previous 6 months, 2008
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Items identified as being significant (at P < 0.1) in univariate analysis (age, education, employment, sexual identity, HIV serostatus, site and city of recruitment, any drug use, having had a regular partner in the previous 6 months, and anal intercourse with casual partners) were included in the multivariate analysis. In multivariate analysis, being somewhat older, using drugs, being HIV-positive, living in Melbourne, being recruited at a sex venue, having university education, and engaging in anal intercourse, both with a condom and without a condom, were independently associated with having engaged in group sex (Table 4). Apart from education, these same items were also independently associated with having engaged in group sex at least monthly.

Table 4 Multivariate associations with group sex during previous 6 months, 2008
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Discussion

Men who engaged in group sex, and particularly those that did so more often, were more likely to engage in anal intercourse, both with and without a condom, with both their regular and casual partners. They were also more likely to report drug use, and more frequent drug use, and to have been recruited in sex venues.

Melbourne men were somewhat more likely to have been recruited in sex venues (data not shown) but as living in Melbourne was independently associated with group sex, there may be additional aspects of gay sexual subcultures in Melbourne which distinguish that city from the others in this sample. Men who were somewhat older were also more likely to report group sex. This reflects previously reported findings that Australian gay men in their 30–40s in particular are more sexually active and adventurous than their younger counterparts [16]. Other socio-economic indicators, such as education, suggest that there may be class-related factors involved in the likelihood to engage in group sex. We were unable to explore these issues of class and geography further in these data.

HIV-positive men were more likely to engage in group sex, though not necessarily any more frequently, than non HIV-positive men, and they were more likely to engage in UAIC. Some of the UAIC reported by HIV-positive men would have included positive–positive sex, where both partners were HIV-positive [1, 17], but, nonetheless, HIV-positive men who engaged in group sex were noticeably more likely to also report UAIC. However, regardless of the respondents’ own HIV serostatus, those who engaged in group sex were more likely to also report UAIC.

The older age, higher HIV prevalence, greater likelihood to engage in anal intercourse, including UAI, and greater use of drugs among men who engaged in group sex in this sample indicates that these men are not unlike other men recruited through group sex networks [1]. These data strongly support the argument that ‘intensive sex partying’ contexts, where sex with multiple partners and drug use are often used in combination to maximise the experience, is an appropriate high priority for targeted HIV and STI prevention [12].

We recruited this community-based sample through a broad range of sites in the local gay communities. Our findings are, however, at least restricted to urban gay men, and the extent to which they can be applied to other populations and other locations is unclear. Also, the Australian context may not always correspond to that found in other countries, and at least some of the differences between these data and those observed elsewhere may be due to those wider differences between countries. In particular, the relatively high rates of HIV testing among gay men in Australia may mean that sexual risk behaviour is understood differently by Australian gay men compared with gay men in other countries where testing rates are lower. Also, the GCPS is based on a relatively brief questionnaire designed to monitor risk behaviours over time. While we were able to identify patterns of behaviour, there is little capacity in these data to explore the reasons and motivations for those behaviours. Also, while sexual identity was not an independent predictor of likelihood to engage in group sex, this was a sample overwhelmingly of gay-identified men and men with strong connections to local Australian gay communities, and the findings may not apply to other men who have sex with men. Some men reporting UAIC may have been using some other method of risk-reduction, such as strategic positioning or serosorting. Although we collected information on sexual position during UAIC, information about the HIV serostatus of casual partners was not available in this survey.

Although it is not possible to determine from these data whether the risk behaviour reported by these men occurred in the context of group sex, it is clear that men who engaged in group sex were in general taking risks more often compared with those who did not. This was particularly true of men who engaged in group sex more frequently. Also, the greater likelihood for HIV-positive men to report UAIC that has often been reported [16] appears in this study to apply especially to those HIV-positive men who also engaged in group sex.

Conclusion

Our findings confirm that group sex is a relatively common activity among homosexually active men in Australia, and that those who engage in group sex are at high risk of HIV and STI transmission and infection. This is likely to be particularly true of men within sexually adventurous networks [12]. Group sex among gay men, and the sexual networks in which this occurs, are an important priority for targeted HIV prevention activities and research. Further investigation into the motivations for and contexts of risk behaviours during group sex is needed. Nonetheless, these data suggest that targeted HIV prevention within this population, where the potential for HIV and STI transmission is exacerbated by high levels of partner concurrency and of prevalence of sexually transmitted infections, would potentially have a significant impact on incidence rates of HIV and other STI.