Received Apr 19; Accepted Sep Abstract Background Respondent-driven sampling RDS is a method of approximating random sampling of populations that are difficult to locate and engage in research such as gay, bisexual and other men who have sex with men GBM. However, its effectiveness among established urban gay communities in high-income countries is largely unexplored outside North America.
Compensation was given for participating and for each peer enrolled. Feedback on the pilot was obtained through questionnaire items, participant follow-up, and a focus group. Nine seeds commenced recruitment, directly enrolling 10 participants Wave One , who in turn enrolled a further three Wave Two. Participants were motivated by altruism above financial incentives; however, time, transport and reluctance recruiting peers were perceived as barriers to enrolment.
Discussion Slow recruitment in our pilot study suggests that RDS might not be an effective or efficient method of sampling gay men in all high-income urban settings. However those who participated in the pilot were willing to provide anal swabs and information on their sexual behaviour, and also on the size of their GBM social network which is necessary to weight data in RDS.
Refinements and adaptations such as reducing the transaction costs of taking part e. Respondent-driven sampling, Gay and bisexual men, Sexually transmitted infections, HIV, Probability sample, Pilot study, Feasibility study, Formative assessment, New Zealand Background Respondent-driven sampling RDS is a method that is purported to approximate a random sample in populations that are difficult to locate and engage in research.
It is a form of chain-referral sampling in which participants are also each asked to recruit a limited number of eligible peers. Because participation in RDS studies typically requires presentation to a physical study location, it also enables both biological specimens and behavioural data to be collected.
In spite of the strong theory on which RDS is based, there is limited evidence that it has actually been a valuable method to research GBM across a range of settings. Anecdotally several attempts have been unsuccessful or have violated key assumptions [ 3 ]. This is despite the potential of RDS to provide superior estimates than the more commonly used gay community convenience sampling.
Furthermore, Western European and Australasian countries generally have tolerant socio-legal environments towards homosexuality which should make RDS fieldwork comparatively simpler. Research examining the viability of RDS in these settings is needed. New Zealand has an existing programme of non-random, purposive, community-based and web-based HIV behavioural surveillance among GBM [ 11 ], which has been used to collect oral fluid specimens [ 12 ].
However, collection of more comprehensive and invasive biological specimens for estimating STI prevalence among the GBM population, such as rectal specimens, is less feasible using these programmes. A quasi-probability sample derived through RDS, in which participants were willing to attend a centre and provide such specimens, would therefore be valuable.
Methods Formative assessment The pilot study was designed by adapting the methods of Johnston [ 13 ]. It was conducted in Auckland, a sprawling multicultural city of 1. Auckland has the largest GBM population in New Zealand that is geographically clustered in the inner city [ 14 ]. Public and civic celebration of gay, bisexual, lesbian and transgender communities is common. It was agreed this would make an ideal environment for the use of RDS as almost all GBM would have a non-zero probability of being recruited, despite the possibility of sampling bottle-necks.
The NZAF Burnett Centre, a community-based HIV-testing facility, was utilised for the study due to its central location, facilities to perform the study procedures, and public transport access. Seeds Nine GBM from a range of ethnic groups 3 Maori, 2 Pacific, 2 Asian and 2 New Zealand European with at least one in each group aged under and over 30 were selected as seeds to initiate recruitment.
Wave Two participants were not asked to recruit further peers in this pilot, but would be in a full study. No appointment was necessary to attend the study site. A part-time research assistant was employed to administer the study procedures on-site. Participants were required to provide a mobile phone number which was destroyed at the conclusion of the pilot for follow-up and to receive results if they tested positive.
Participants completed the study procedures on-site and were then provided with coupons—which had to be exchanged physically—to give to up to three eligible GBM they knew and who knew them.
Coupons gave the study location, opening hours, contact number and brief information about the study. Movie vouchers, to the value of NZD 30 approximately EUR 18 , were provided on participation, with another for each peer successfully recruited i.
Alternatively, participants could ask that the equivalent be donated to a GBM-aligned charity. Therefore as with all RDS studies there was a dual incentive for participation: Questionnaire Questionnaires were self-completed on-site and deposited into a secure box. Rectal specimens are also difficult to collect in traditional convenience-based research settings such as at community events.
Participants were asked to self-administer a rectal swab on-site using a Roche Corbas swab kit. Specimens were anonymously linked to participants by the respondent ID and sent to a laboratory for nucleic acid amplification testing NAAT for Chlamydia trachomatis and Neisseria gonorrhoea. Positive results were communicated to participants by the research assistant. Evaluation Three ways were used to solicit feedback about the pilot study. Secondly, on redemption of coupons, both the seeds and Wave One participants were asked about people who declined to participate and their perceived reasons for doing so.
Thirdly, a post-study focus group was conducted by an independent researcher with some seeds and Wave One participants.
We selected a range of participants for this including those who had successfully recruited peers and those who had not. The focus group explored their understanding of the study process, compensation, site access, and barriers to participation. The nine original seeds enrolled 10 participants; three recruiting the maximum of three peers within the 2-week limit, one recruited one and five none. These 10 in turn enrolled a further three; one each by three.