Pragmatic trial of a Study Navigator Model (NAU) vs. Ambassador Model (N+) to increase enrollment to health research among community members who use illicit drugs.

Background: Although drug use is common in the population, drug users are sometimes excluded from research without justification. Two models of individualized study matching were compared for effectiveness in enrolling people who "endorsed current drug use" and those who "did not" into appropriate research.

Methods: Participants in the NIDA-funded Transformative Approach to Reduce Research Disparities Towards Drug Users study (Navigation Study) were recruited through a Clinical and Translational Science Award (CTSA) community engagement model. Of the 614 community-recruited adults, 326 endorsed current drug use (cases); 288 did not (controls). Participants were randomized to one of two intervention groups: Navigation as Usual (NAU) [individualized study matching through a Study Navigator] or Enhanced Navigation (N+) [individualized study matching plus transportation and other assistance through an Ambassador]. Rates of enrollment into research studies were compared.

Results: At 90 days, N+ vs. the NAU intervention was associated with higher enrollment among both drug users (36.0% N+ vs. 24.9% NAU) and non-drug users (45.5% N+ vs. 25.2% NAU). NAU attained the same rate of enrollment for users of drugs (24.9%) and non-users (25.2%); N+ had similar rates as well (36.0% drug users vs. 45.5% non-drug users). In addition, high rates of enrollment were achieved among all groups of participants, from 24.9% (drug users in NAU) to 45.5% (non-drug users in N+).

Conclusions: Both the NAU and N+ methods can reduce barriers and help users and non-users become part of the population that participates in research. Working with the local CTSA adds significant value to the research enterprise.