Evidence-Based Preventive Intervention for Preadolescent Aggressive Children: One-Year Outcomes Following Randomization to Group Versus Individual Delivery

Objective: Some research suggests that group interventions with antisocial youth may, on occasion, have iatrogenic effects. This is the first study to test the effects of group versus individual delivery of evidence-based intervention for aggressive children. Method: Three hundred sixty fourth-grade children were randomly assigned by school to group coping power (GCP) or individual coping power (ICP). Longitudinal assessments of teacher and parent reports of behavior (Behavior Assessment System for Children [BASC]; Peer Affiliation and Social Acceptance [PASA]) were collected from baseline through a 1-year follow-up. Results: Growth curve analyses revealed that children in both conditions reduced teacher- and parent-reported externalizing behavior problems and internalizing behavior problems by the end of the 1-year follow-up. However, the degree of improvement in teacher-reported outcomes was significantly greater for children receiving an individual version of the program. In addition, children's baseline level of inhibitory control moderated intervention effects, showing children with low initial levels of inhibitory control to respond poorly in teacher-rated outcomes to group interventions compared to those delivered individually. Conclusions: This study suggests overall benefits to children for either group or individual delivery of the Coping Power program under high-fidelity conditions; however, for children with low levels of initial self-regulation, individualized interventions will likely yield the most significant reduction in externalizing behavior in the school setting in preadolescence. What is the public health significance of this article? This study finds that group formats for aggressive children can limit intervention effects in school settings for some children.