Methods to recruit and retain a cohort of young-adult injection drug users for the Third Collaborative Injection Drug Users Study/Drug Users Intervention Trial (CIDUS III/DUIT).

BACKGROUND New injection drug users (IDUs) are at high risk for blood-borne viral infections. Given U.S. policy to only fund proven-effective HIV prevention interventions, insights into conducting intervention trials among young IDUs are provided here by describing methods and participants' characteristics in the CIDUS III/DUIT study. METHODS In 2002-2004, 15-30-year-old IDUs in Baltimore, Chicago, Los Angeles, New York, and Seattle were recruited through community outreach, advertising and coupon-based participant referrals. Baseline interviews assessed sociodemographics, injection, and sexual behaviors. Antibody tests for HIV and hepatitis A, B, and C viruses (HAV, HBV, and HCV) were conducted. IDUs who were HIV and HCV antibody negative at baseline were eligible to participate in a randomized controlled HIV/HCV prevention trial. Follow-up assessments were conducted 3 and 6 months post-intervention. Data were analyzed to identify participant differences at baseline by city, trial enrollment, and trial retention. RESULTS Baseline assessments were completed by 3285 IDUs. Participants were mean age 23.8 years, 69% male, 64% White, 17% Hispanic, and 8% Black. Seroprevalence of HIV, HCV, HBV, and HAV antibodies were 2.9, 34.4, 22.4, and 19.3%, respectively. Of the 2062 (62.7%) baseline participants who were HIV and HCV antibody negative, 859 (41.7%) were randomized. At least one follow-up assessment was completed by 712 (83%) randomized participants. Contextual factors, primarily homelessness, were associated with lower enrollment and retention. CONCLUSIONS Recruitment and retention of young-adult IDUs for complex intervention trials is complicated, yet feasible. Risk behaviors among participants enrolling in and completing the trial reflected those eligible to enroll.