Respondent-Driven Sampling in a Study of Drug Users in New York City: Notes from the Field

Abstract

Beth Israel Medical Center (BIMC), in collaboration with the Centers for Disease Control (CDC) and the New York State Department of Health (NYSDOH), used respondent-driven sampling (RDS) in a study of HIV seroprevalence among drug users in New York City in 2004. We report here on operational issues with RDS including recruitment, coupon distribution, storefront operations, police and community relations, and the overall lessons we learned. Project staff recruited eight seeds from a syringe exchange in Lower Manhattan to serve as the initial study participants. Upon completion of the interview that lasted approximately 1 h and a blood draw, each seed was given three coupons to recruit three drug users into the study. Each of the subsequent eligible participants was also given three coupons to recruit three of their drug-using acquaintances. Eligible participants had to have: injected, smoked or snorted an illicit drug in the last 6 months (other than marijuana), aged 18 or older, adequate English language knowledge to permit informed consent and complete questionnaire. From April to July 2004, 618 drug users were interviewed, including 263 (43%) current injectors, 119 (19%) former injectors, and 236 (38%) never injectors. Four hundred sixty nine (76%) participants were men, 147 (24%) were women, and two (G1%) were transgender. By race/ethnicity, 285 (46%) were black, 218 (35%) Hispanic, 88 (14%) white, 23 (4%) mixed/not specified, and four (G1%) native American. Interviews were initially done on a drop-in basis but this system changed to appointments 1 month into the study due to the large volume of subjects coming in for interviews. Data collection was originally proposed to last for 1 year with a target recruitment of 500 drug users. Utilizing RDS, we were able to recruit and interview 118 more drug users than originally proposed in one quarter of the time. RDS was efficient with respect to time and economics (we did not have to hire an outreach worker) and effective in recruiting a diverse sample of drug users.

Respondent-driven sampling in a syringe exchange setting

“…On the other hand, although this process of chain-referral reached both primary heroin and amphetamine users, despite the fact that all the most generative seeds were heroin users, non-injecting drug users or clients not attending the SeP were not reached. Also, the recruitment process was slower in our study than in the study by mcknight and coworkers [5], where the seeds were also SeP clients. The fact that non-SeP clients were not reached in our study is also in contrast to the study of mcknight and co-workers [5], where 19% of clients in the final study material were ex-injectors and 38% never-injectors.…”

“…Also, the recruitment process was slower in our study than in the study by mcknight and coworkers [5], where the seeds were also SeP clients. The fact that non-SeP clients were not reached in our study is also in contrast to the study of mcknight and co-workers [5], where 19% of clients in the final study material were ex-injectors and 38% never-injectors. This different finding in the present study, although in a markedly smaller group of subjects, may be related to features of the recruitment process carried out here, or to characteristics of the SeP population assessed Table II.…”

A Comparison Between Respondent-Driven Sampling and Time-Location Sampling Among Men Who Have Sex with Men in Shenzhen, China

“…In such research fields, sensitive issues or marginalized populations are often involved, making it difficult to acquire representative data. Our study and previous research revealed that both RDS and TLS can successfully sample marginalized populations such as MSM, female sex workers, drug users and migrants (Ferreira et al, 2008;Johnston, Sabin, Hien, & Huong, 2006;McKnight et al, 2006). We highly recommend researchers to consider these two sampling methodologies to improve representativeness of their data when targeting marginalized populations.…”

Condom Use with Female Sex Workers among Male Clients in Sichuan Province, China: The Role of Interpersonal and Venue-Level Factors

“…16 While standard probability sampling methods may not be feasible to recruit CSMCs, future studies should consider alternative sampling strategies, such as respondent-driven sampling, which has been shown to have greater external validity among hidden populations. [37][38][39] Finally, similar to previous studies measuring venue-level factors in commercial sex establishments, 24 the assessment of venue-level factor in this study was based on the participants' self-reported data, rather than observed data, such as the actual supply of condom use.…”