"Who gets in?" Recruitment and screening processes of outpatient substance abuse trials.

A brief telephone-screening interview was conducted with 1759 callers seeking treatment for substance abuse at the Treatment Research Clinic (TRC) over a 16-month period. The purpose of this study was to examine the effectiveness of various recruitment methods in attracting eligible participants and to identify screening variables that characterized eligible and ineligible callers. Callers referred by friends and family were more likely to be eligible than callers from other referral sources. Callers seeking treatment for cocaine abuse who reported more severe alcohol/substance problems were more likely to be eligible for treatment protocols, while those with severe problems in other psychosocial areas (legal, medical, and psychiatric) were more often excluded. Alcohol- and nicotine-dependent callers reporting severe alcohol problems were more likely to be eligible but otherwise were not different from callers who were ineligible. The effectiveness of recruitment methods may not be the same for different types of substance use disorders. This study underscores the importance of having a sensitive screening assessment for recruiting a homogeneous yet representative sample for outpatient substance abuse clinical trials.