Using a Meta-analytic Technique to Assess the Relationship between Treatment Intensity and Program Effects in a Cluster-Randomized Trial

School bullying and delinquent behaviors are persistent and pervasive problems for schools, and have lasting effects for all individuals involved (Copeland et al., JAMA Psychiatry 70:419-426, 2013; Espelage et al., J Res Adolesc 24(2):337-349, 2013a). As a result, policymakers and practitioners have attempted to thwart these ill-effects using school-based interventions. Recent meta-analyses have found, however, that these programs produce only moderate effects (Ttofi and Farrington, J Exp Criminol 7:27-56, 2011). Consequently, it is important to investigate further the reasons for such findings. One promising analysis is to assess the relation between treatment intensity variables and program outcomes. Unfortunately, few treatment intensity variables have been utilized in the school-based prevention literature, and it is often cumbersome to model the relation between treatment intensity and outcomes. The purpose of this project, therefore, is to explicate novel measures of treatment intensity and delineate a relatively new meta-analytic technique to model the relation between the variables and program effects. The context for this project is a large-scale, multi-site, cluster-randomized trial; 36 schools and 3,616 students participated in three waves of data collection. The results indicated that, for the second wave of data collection, stronger treatment effects were found when teachers and program implementers spent a greater amount of time prepping lessons, provided additional financial resources, and received outside consultation and support.