Home-based chlamydia testing of young people attending a music festival – who will pee and post?

Abstract

Background: Chlamydia is most common among young people, but only a small proportion of Australian young people are tested annually. Home-based chlamydia testing has been piloted in several countries to increase testing rates, but uptake has been low. We aimed to identify predictors of uptake of home-based chlamydia testing to inform future testing programs.

Methods: We offered home-based chlamydia testing kits to participants in a sexual behavior cross-sectional survey conducted at a music festival in Melbourne, Australia. Those who consented received a testing kit and were asked to return their urine or vaginal swab sample via post.

Results: Nine hundred and two sexually active music festival attendees aged 16-29 completed the survey; 313 (35%) opted to receive chlamydia testing kits, and 67 of 313 (21%) returned a specimen for testing. One participant was infected with chlamydia (1% prevalence). Independent predictors of consenting to receive a testing kit included older age, knowing that chlamydia can make women infertile, reporting more than three lifetime sexual partners and inconsistent condom use. Independent predictors of returning a sample to the laboratory included knowing that chlamydia can be asymptomatic, not having had an STI test in the past six months and not living with parents.

Conclusions: A low proportion of participants returned their chlamydia test, suggesting that this model is not ideal for reaching young people. Home-based chlamydia testing is most attractive to those who report engaging in sexual risk behaviours and are aware of the often asymptomatic nature and potential sequelae of chlamydia infection.

Background

Chlamydia (Chlamydia trachomatis) is the most prevalent bacterial sexually transmitted infection (STI) in the western world[1] and the most common notifiable infectious disease in Australia[2]. Rates of chlamydia infection are increasing worldwide, and Australian notification rates quadrupled from 1999 to 2008[2]. Infection is concentrated in youth, with approximately 80% of notifications being among those aged 15 to 29 years[2]. Chlamydia infection can cause significant morbidity, particularly for women: up to two-thirds of cases of tubal infertility and one-third of cases of ectopic pregnancy may be attributable to chlamydia infection[3]. Over 80% of infections are asymptomatic,[3] making screening necessary to detect and treat cases.

Despite being the population group at highest risk of STIs, young Australians know little about STIs other than HIV[4]. Only 12% of women and 5% of men aged 16-29 years in Australia who attended a doctor in 2007-2008 had a chlamydia test[5] – far lower than the testing rate of 40% amongst those aged less than 25 years estimated to be required for a rapid reduction in chlamydia prevalence in Australia[6].

Flexibility and ease of testing have been identified as potential factors in promoting chlamydia testing[7]. Home-based chlamydia testing has been trialled in the US, Europe, Australia, and elsewhere to increase screening rates and make testing more accessible[8-13]. Vaginal and penile swabs, and urine samples, have been collected at home and returned to laboratories by post for testing. These methods are acceptable to young people,[13-17] and participants in a study in the US who were tested both at a clinic and at home preferred home-testing[17].

Nonetheless, uptake of home-based testing is generally low[9]. Response rates for home-testing kits distributed by mail in the Netherlands, Sweden, the UK, South Africa, and Brazil ranged from 24-80%[11,12,18-20]. Previous researchers distributed home-testing kits at pharmacies, gyms and other community settings, with return rates of 3-38%[13,15,21,22]. In studies in which kits were advertised and could be ordered, 30-68% of people who ordered a kit returned a specimen[15,23].

Few studies have collected information on correlates of home-based chlamydia testing uptake. In two studies, common reasons for declining testing included being in a steady relationship,[18] consistent condom use,[18] not being sexually active,[18,19] and lack of interest in testing[ 19]. In one study, univariate analysis found that nonrespondents were less likely to report symptoms consistent with STIs or to have ever had sex, and sexually active female non-respondents were more likely to have used a condom at last sexual contact (no multivariate analysis was conducted)[19].

Given that uptake is low, knowledge of predictors of uptake of testing among sexually active young people is required to appropriately target home-based chlamydia testing to ensure program efficiency and maximise program participation. From a pragmatic perspective, the extent to which the target group for outreach chlamydia testing (young people at risk of acquiring chlamydia who are under-utilising related services) is willing to take up home-based testing is of particular importance for targeting programs efficiently. In order to maximise program utilisation, measurement of the extent to which modifiable factors (such as knowledge of chlamydia) predict uptake is also important.

This analysis aimed to identify determinants of ordering and returning chlamydia testing kits in a community setting in order to inform future testing programs. Since 2005, we have conducted cross-sectional surveys of sexual risk behaviour by people aged 16-29 attending a large annual music festival in Melbourne, Australia[24]. In 2009, we invited all participants to receive a chlamydia testing kit posted to their homes.

Methods

Design
A cross-sectional survey was conducted at the Big Day Out music festival in Melbourne, Australia in January 2009. Survey participants were invited to consent to receive a chlamydia testing kit by post.

Setting and recruitment
The Big Day Out is a music festival held annually in Australasia featuring a diverse selection of music [25]. The Melbourne Big Day Out draws 40-50,000 fans, mostly young people. Our Big Day Out recruitment site consisted of a market stall positioned in the shade with chairs for participants. Participants either approached the stall or were approached by recruitment staff and asked to complete a brief questionnaire about ‘sex, drugs and rock’n’roll’. Approximately 20 trained researchers recruited participants. Festival attendees were eligible for participation if they were aged between 16 and 29 years, were not intoxicated, and had sufficient English language skills to complete a self-administered questionnaire.

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