Measuring participation in a prevention trial with parents of young children.

This paper describes parent participation in a clinical trial of preventive parent training (PT) targeting low-income parents of young children. Participation encompassed enrollment, attendance, and engagement. Average enrollment rate was 34.9%, although enrollment rates were significantly higher in the control (39.1%) than in the intervention (30.6%) centers. Parents attended an average of 39% of the PT sessions. Higher attendance was associated with lower parenting self-efficacy, more parent-reported child behavior problems, and attending the first PT session. Level of engagement in the PT sessions was related to improvements in parent and child outcomes. Findings suggest that attendance is linked to parent perceived need for help and that resources should be focused on ensuring parent attendance at the first intervention session.