Communities That Care (CTC), an evidence-based prevention system, has been installed outside of a research context in over 500 communities worldwide. Yet, its effectiveness in a non-research context is unknown. Using a repeated cross-sectional design with propensity score weighting at the school district-level, the purpose of this study was to examine the effect of widespread diffusion of CTC across Pennsylvania on adolescent substance use, delinquency, and depression. Anonymous youth survey data were collected from 6th, 8th, 10th, and 12th grade students every other year from 2001 to 2011. Three-hundred eighty-eight school districts participated in one to six waves of data collection during that time, resulting in a total of 470,798 student-reported observations. The intervention school districts received programming provided by CTC coalitions. Outcome measures were lifetime and past 30-day alcohol, tobacco, marijuana, and other drug use. Lifetime and past year participation in delinquency and current depressive symptoms were also analyzed. Analyses revealed that CTC school districts had significantly lower levels of adolescent substance use, delinquency, and depression. This effect was small to moderate, depending on the particular outcome studied. Overall effects became stronger after accounting for use of evidence-based programs; there are likely differences in implementation quality and other factors that contribute to the observed overall small effect size. Future research needs to unpack these factors.
Keywords: Communities That Care (CTC); Dissemination; Effectiveness; Evidence-based programs; Outcomes; Policy change.