title: Evaluating outcome-correlated recruitment and geographic recruitment bias in a respondent-driven sample of people who inject drugs in Tijuana, Mexico.
abstract: Respondent-driven sampling's (RDS) widespread use and reliance on untested assumptions suggests a need for new exploratory/diagnostic tests. We assessed geographic recruitment bias and outcome-correlated recruitment among 1,048 RDS-recruited people who inject drugs (Tijuana, Mexico). Surveys gathered demographics, drug/sex behaviors, activity locations, and recruiter-recruit pairs. Simulations assessed geographic and network clustering of active syphilis (RPR titers ≥1:8). Gender-specific predicted probabilities were estimated using logistic regression with GEE and robust standard errors. Active syphilis prevalence was 7 % (crude: men = 5.7 % and women = 16.6 %; RDS-adjusted: men = 6.7 % and women = 7.6 %). Syphilis clustered in the Zona Norte, a neighborhood known for drug and sex markets. Network simulations revealed geographic recruitment bias and non-random recruitment by syphilis status. Gender-specific prevalence estimates accounting for clustering were highest among those living/working/injecting/buying drugs in the Zona Norte and directly/indirectly connected to syphilis cases (men: 15.9 %, women: 25.6 %) and lowest among those with neither exposure (men: 3.0 %, women: 6.1 %). Future RDS analyses should assess/account for network and spatial dependencies.
authors: The Calverton Center, Pacific Institute for Research and Evaluation, 11720 Beltsville Drive Suite 900, Calverton, MD, 20705, USA, arudolph@pire.org.
authors: Abby E
authors: AE
authors: Rudolph
authors: Tommi L
authors: TL
authors: Gaines
authors: Remedios
authors: R
authors: Lozada
authors: Alicia
authors: A
authors: Vera
authors: Kimberly C
authors: KC
authors: Brouwer
mesh_terms: D000328:Adult; D015982:Bias; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D018579:Patient Selection; D015995:Prevalence; D012307:Risk Factors; D012494:Sampling Studies; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000453:epidemiology*; D013587:Syphilis / Q000453:epidemiology* / Q000517:prevention & control; D014376:Tuberculosis / Q000453:epidemiology* / Q000517:prevention & control