Recruitment and retention of participants in prevention trials involving family-based interventions.

Family-based preventive intervention trials in the area of child conduct problems face serious challenges regarding the recruitment and subsequent retention of participants. This article focuses on the problems and strategies pertinent to recruitment and retention in prevention research. The issues are discussed first with respect to initiating and maintaining a longitudinal sample, and then engaging and sustaining families in a preventive intervention. General principles are illustrated by EARLY ALLIANCE, a recently launched preventive intervention trial aimed at reducing children's risk for conduct disorder, substance abuse, and school failure. Recommendations for enhancing recruitment and retention are offered.