Recruiting hard-to-reach drug-using men who have sex with men into an intervention study: lessons learned and implications for applied research.

Drug (ab)use researchers and service providers across the globe have been challenged with locating target populations and subsequently enrolling participants into their programs. This study presents data from nearly 3 years (2004-2006) of recruiting "high-risk" drug-using gay and bisexual men into a clinical research trial based in New York City. During the enrollment period, two recruitment/marketing strategies were utilized: (1) marketing of the intervention research study itself to men who were in the early stages of identifying problems with their drug use and risky sexual behavior and (2) two-stage recruitment via a lower-threshold/commitment (i.e., brief survey) and subsequent offering/enrollment into the full trial upon completion of the initial visit (i.e., a foot-in-the-door). The second approach was substantially more effective in enrolling participants into the full trial (6.3 participants/month vs. 2.5 participants/month). Furthermore, recruitment costs for the foot-in-the-door approach were substantially reduced ($356.57 per participant vs. $497.03 per participant). Compared to the marketing of interventions themselves to target populations, a two-stage recruitment strategy incorporating lower-threshold interactions may be a more effective approach to recruit for interventions.