“Starfish Sampling”: a Novel, Hybrid Approach to Recruiting Hidden Populations

Abstract

We sought to leverage the strengths of time location sampling (TLS) and respondent-driven sampling (RDS) for surveys of hidden populations by combing elements of both methods in a new approach we call Bstarfish sampling.^Starfish sampling entails random selection of venue-daytime units from a mapping of the locations where the population can be found, combined with short chains of peer referrals from their social networks at the venue or presenting to the study site later. Using the population of transmen in San Francisco as a case example, we recruited 122 eligible participants using starfish sampling: 79 at randomly selected venues, 11 on dating applications, and 32 by referral. Starfish sampling produced one of the largest communityrecruited samples specifically for transmen to date. Starfish sampling is a flexibility method to recruit and sample hidden populations for whom conventional TLS and RDS may not work in theory or practice.

High HIV prevalence among transgender women in Paraguay

“…We also recognize uncertainties in the statistical approach to analyze the data obtained by our hybrid sampling design. 15 The present report treats the data as starting from a simple random sample of venues and clients with adjustment of the standard errors using the randomly selected venue or client as a single-stage sampling unit, with 61 units in the present case. We acknowledge this is a simplification as further recruitment of peers stems from these initial random primary sampling units with uncertain probability.…”

“…To efficiently reach trans women for this study, we used a hybrid sampling design called 'starfish sampling' that was previously developed for research with trans men in San Francisco, USA. 15 Starfish sampling combines venue-based and peerreferral methods. Sampling entails creating a map or 'universe' of venues where trans women can be found and randomizing these sources for recruitment, as in time-location sampling.…”

“…Sampling entails creating a map or 'universe' of venues where trans women can be found and randomizing these sources for recruitment, as in time-location sampling. 15,16 Venue-based recruitment is followed by enlisting participants to refer eligible peers from their social networks, as in respondent-driven sampling, 16 although typically resulting in shorter chains of recruitment. 15 The mapping of venues included sites where trans women are engaged in sex work and places where our partnering non-governmental organizations (NGOs) provide outreach.…”

“…15,16 Venue-based recruitment is followed by enlisting participants to refer eligible peers from their social networks, as in respondent-driven sampling, 16 although typically resulting in shorter chains of recruitment. 15 The mapping of venues included sites where trans women are engaged in sex work and places where our partnering non-governmental organizations (NGOs) provide outreach. The present study added the random selection of clients of programs serving trans women for recruitment and for peer referrals.…”

Exploring associations between place of sex work and HIV vulnerabilities among sex workers in Jamaica

“…Future studies could conduct respondent driven or starfish sampling to enhance the representativeness of the sample. 34 Depression symptoms were assessed over the past two weeks, while HIV serostatus was assessed over the lifetime. It is possible that there is a bidirectional association between depression and HIV-positive serostatus that we were unable to assess in this cross-sectional study.…”