Recruitment and retention strategies in clinical studies with low-income and minority populations: Progress from 2004-2014.

More than 20years have passed since the NIH 1993 Act was initiated, and while progress has been made toward better representation of minorities and women in clinical research studies, as this review will show, there is still tremendous room for improvement. The purpose of this review was to identify the current state of literature on recruitment and retention strategies in clinical studies of low-income and minority populations. We identified 165 studies published in English between 2004 and 2014. Data extracted included information on the study type (descriptive or analytical), study design, study focus (recruitment, retention, both recruitment and retention), health outcome, specific minority group, special population or age group, if specific recruitment/retention techniques were tested, and key research findings. Particular attention was given to articles that statistically analyzed the effectiveness of recruitment and retention strategies on enrollment/retention rates. Effective recruitment and retention strategies for low-income and minority groups, differential effectiveness across groups, and implications for future research are discussed.