Using Complier Average Causal Effect Estimation to Examine Student Outcomes of the PAX Good Behavior Game When Integrated with the PATHS Curriculum

A growing body of research has documented a link between variation in implementation dosage and outcomes associated with preventive interventions. Complier Average Causal Effect (CACE; Jo, 2002) analysis allows for estimating program impacts in light of variation in implementation. This study reports intent-to-treat (ITT) and CACE findings from a randomized controlled trial (RCT) testing the impacts of the universal PAX Good Behavior Game integrated with Promoting Alternative Thinking Strategies (i.e., PATHS to PAX) and PAX GBG only compared to a control, using ratings by 318 K-5 teachers of 1,526 at-risk children who, at baseline, were rated as displaying the top 33rd percentile of aggressive-disruptive behavior. Leveraging a prior study on these data (Berg et al., 2017), CACE was defined as the effect of intervention assignment for compliers, using two compliance cut points (50th and 75th percentile), on posttest ratings of student academic engagement, social competence, peer relations, emotion regulation, hyperactivity, aggressive-disruptive behavior. The ITT analyses indicated improvements for students in the integrated condition on ratings of social compared to the control condition. The CACE analyses also indicated significant effects of the integrated intervention on social competence, as well as academic engagement and emotion regulation for students in high compliance classrooms. These findings illustrate the importance of considering variation in implementation within the context of RCTs. [This paper was published in "Administration and Policy in Mental Health and Mental Health Services Research" v47 n6 p975-986 2020.]