Subpopulations of Illicit Drug Users Reached by Targeted Street Outreach and Respondent-Driven Sampling Strategies: Implications for Research and Public Health Practice

Abstract

Purpose-To determine whether illicit drug users recruited through Respondent-Driven Sampling (RDS) and targeted street outreach (TSO) differ by comparing two samples recruited concurrently with respect to sample selection and potential recruitment biases.Methods-217 heroin, crack, and cocaine users aged 18-40 were recruited through TSO in New York City (2006)(2007)(2008)(2009). 46 RDS seeds were recruited similarly and concurrently yielding a © 2010 Elsevier Inc. All rights reserved.Correspondence: Abby Rudolph, Mailing Address: 3422 Keswick Rd, Baltimore MD 21211, Abby.Rudolph@gmail.com, Phone: 267-261-6395. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conclusion-These data suggest that RDS and TSO strategies reach different sub-groups of drug users. Understanding the differing capabilities of each recruitment strategy will enable researchers and public health practitioners to select an appropriate recruitment tool for future research and public health practice. KeywordsRespondent Driven Sampling; Targeted Street Outreach; HIV; illicit drug users; sampling biasGenerating a representative sample of illicit drug users for substance abuse and HIV research can be challenging because there is no sampling frame. While convenience, targeted, snowball and time-location sampling methods are used to recruit this population, volunteer and masking biases may result from the inability to sample randomly from the target population. Respondent-Driven Sampling (RDS) aims to reduce these biases with a modified form of chain-referral sampling that regulates peer recruitment and uses probability weights to offset nonrandom recruitment.RDS has recruited geographically(1-3) and demographically diverse samples of injection drug users (IDUs).(4-9) Like samples recruited with other strategies, respondent-driven samples include IDUs from both institutional settings and public venues. RDS also recruits those missed by traditional strategies: those only identified through social networking approaches or through their participation in activities that define the hidden population.(10)Studies comparing respondent-driven samples with chain referral(11), targeted(12,13), traditional outreach(1,2), snowball (14) and time-location samples(3,14,15) have reported differences in demographic characteristics (1,11,12,14), but not in HIV risk behaviors(11).Results from comparison studies should be interpreted with caution, because comparison samples were often recruited over different enrollment periods(14-16) and from different geographic locations.(17) For example, in a study comparing samples rec...

Characteristics and Health Service Utilization in Two Samples of Young Injection Drug Users Recruited Using Direct and Referral Methods in San Francisco, California

“…As well, a higher portion of the RDS sample accessed services including: drug treatment, having obtained needles from an SEP, and reported visiting a medical provider in the last three months. This is in contrast to other comparison studies where chain-referral recruiting was found to have reached young IDU with low service utilization [14][15][16]. P-values in Bold indicate no overlap in 95% Confidence Intervals when comparing unadjusted TS point estimates to adjusted RDS point estimates; NA = data not available * RDS = 12 month "recent" referent period; TS = 3 month "recent" referent period Unadjusted = Unweighted There are several limitations to our analysis and the results must be interpreted with caution.…”

Physical Victimization and High-Risk Sexual Partners among Illicit Drug-Using Heterosexual Men in New York City

“…All participants were recruited between July 2006 and June 2009 through targeted street outreach and respondent-driven sampling (RDS) from neighborhoods with high drug use in Brooklyn, Bronx, Manhattan, and Queens and has been described in detail elsewhere. 23,24 In brief, participants were eligible for START if they were between 18 and 40years old and were non-IDUs reporting frequent use of heroin, crack, or cocaine or newly initiated IDUs (n=652). Eligible IDUs reported injecting heroin, crack, or cocaine for 4 years or less and injecting at least once in the past 6 months.…”

The Relationship Between Discrimination and High-Risk Social Ties by Race/Ethnicity: Examining Social Pathways of HIV Risk

“…Detailed methods on recruitment have been published elsewhere. 28 In brief, neighborhoods that were ethnographically mapped as high drug active areas in New York City were targeted and RDS, a chain sampling referral strategy, was employed to reach drug users who were harder to reach. 29,30 Study Design START employed two study designs: (1) a prospective study design among heavy non-IDUs who never injected and used heroin, crack, or cocaine (i.e., used ≥1 year and currently used ≥2-3 times per week in the past 3 months) and (2) a crosssectional study design among recently initiated IDUs (i.e., injected for ≤4 years and currently injected ≥1 in the past 6 months).…”

“…Variables previously identified in the literature as potential confounders to social network characteristics were assessed 27,28,37,38 and accounted for when appropriate as the aim of this analysis was to isolate the effect of discrimination on high-risk social ties regardless of individual-level demographics and behaviors. We assessed age (continuous), gender (male/female), education (Ghigh school education, high school or general equivalency degree, and some college or more), legal income (no income, G$5,000, and ≥$5,000), age at sexual debut (continuous), number of female and male sex partners (continuous), female and male condom use in the past 2 months (always/infrequently), HIV testing frequency (≤3 vs. ≥4 times), selfreported HIV sero-status (yes/no), injection status (yes/no), primary type of drug used (cocaine, crack cocaine, heroin, or polytomous drug use of all three types of drugs equally), and sample strategy (RDS/TSS).…”