Effectiveness of Respondent-Driven Sampling for Recruiting Drug Users in New York City: Findings from a Pilot Study

Abstract

A number of sampling methods are available to recruit drug users and collect HIV risk behavior data. Respondent-driven sampling (RDS) is a modified form of chain-referral sampling with a mathematical system for weighting the sample to compensate for its not having been drawn randomly. It is predicated on the recognition that peers are better able than outreach workers and researchers to locate and recruit other members of a "hidden" population. RDS provides a means of evaluating the reliability of the data obtained and also allows inferences about the characteristics of the population from which the sample is drawn. In this paper we present findings from a pilot study conducted to assess the effectiveness of RDS to recruit a large and diversified group of drug users in New York City. Beginning with eight seeds (i.e., initial recruits) we recruited 618 drug users (injecting and non-injecting) in 13 weeks. The data document both cross-gender and cross-race and -ethnic recruitment as well as recruitment across drug-use status. Sample characteristics are similar to the characteristics of the drug users recruited in other studies conducted in New York City. The findings indicate that RDS is an effective sampling method for recruiting diversified drug users to participate in HIV-related behavioral surveys.

Differing HIV Risks and Prevention Needs among Men and Women Injection Drug Users (IDU) in the District of Columbia

“…For NHBS-IDU-2, a sample of IDU was recruited between August and November 2009 via respondent-driven sampling (RDS), a chain-referral method which accesses hard to reach populations and provides estimates generalizable to the population of networks from which they are drawn; this method has been used in populations of IDU by other authors. [25][26][27][28][29][30][31][32][33][34][35][36] Non-randomly identified "seeds" are given coupons to recruit three people from their social and/or sexual networks to join the study, and each subsequent eligible person completing the interview is provided with up to three coupons with which to recruit their network members. Eligible individuals lived in the metropolitan DC area, were 18 years old and older, and injected drugs in the past 12 months based on verification of injection sites or successful completion of a knowledge screener specific to IDU.…”

Unsafe Injection and Sexual Risk Behavior among Injecting Drug Users in Georgia

“…RDS has been used in various settings to recruit hard-to-reach populations, and its methodology is described in detail elsewhere. [7][8][9] Initial participants, called seeds in RDS, were selected in collaboration with the non-governmental organization (NGO) "Bemoni." After the completion of the behavioral and the biological part of the survey, each participant, including seeds, was given three uniquely coded nonreplicable coupons to recruit three additional peers to participate in the study.…”

Adapting chain referral methods to sample new migrants

“…By recruiting a large number of seeds we hoped to maximize the diversity of our sample by providing ample chances for long referral chains to develop from recruiters, representing different age, employment status, and gender compositions. Following standard RDS practice (Abdul-Quader et al 2006), we limited the number of potential referrals to three, allowing one of these to be a member of the respondent's household, in order to reduce over-representation of large networks in the sample. However, as the results below show, our referral rates were extremely low and hence we continued recruiting 'seeds' throughout the project.…”