Implementation issues and techniques in randomized trials of outpatient psychosocial treatments for drug abusers: recruitment of subjects.

We reviewed nine randomized clinical trials of outpatient psychosocial treatments for drug abuse to ascertain implementation problems and solutions that the researchers developed. The most common problem was subject recruitment. Inadequate recruitment can disrupt a project's timetable, preoccupy its staff, reduce the trial's ability to detect treatment differences, and perhaps result in the trial's abandonment. The causes of recruitment problems include the need for large samples and multiple eligibility criteria, subject reluctance to be a "guinea pig," low client treatment motivation, client dislike of research procedures, clinicians' distrust of research, and difficulties collaborating with treatment agencies. Solutions include realistic assessment of the target population's size, use of mass media, statistical adjustments to minimize unnecessary sample exclusions, variable treatment assignment ratios, and prevention of common collaboration difficulties.