Effects of the communities that care system on cross-sectional profiles of adolescent substance use and delinquency

Introduction Adolescent substance use and delinquency are major public health problems. Although community-based prevention strategies have been recommended to produce population-level reductions in rates of substance use and delinquency, few models show evidence of effectiveness. Purpose To test the efficacy of a community-based prevention system, Communities That Care (CTC), in reducing community rates of problem behaviors, particularly effects on specific profiles of adolescent substance use and delinquency in eighth- and tenth-graders. Methods Twenty-four communities were randomized to CTC intervention or control groups. Data were collected from 14,099 8th- and 10th-grade students in these communities using anonymous cross-sectional surveys in 2004 and 2010 and analyzed in 2012. Outcomes were four different profiles of self-reported substance use and delinquency in 8th grade and five profiles in 10th grade. Results In the cross-sectional 2010 data, there was no intervention effect on the probability of experimenting with substances or of substance use coupled with delinquent activities for either grade. However, tenth-graders in intervention communities were significantly less likely to be alcohol users than those in control communities (OR=0.69, CI=0.48, 1.00). Conclusions Cross-sectional population surveys showed evidence of CTC effects in reducing tenth-grade alcohol users but not experimenters. A community-wide reduction in adolescent alcohol use is important because alcohol is the most commonly used illicit substance during adolescence, and early initiation of alcohol use has been associated with alcohol-related disorders in adulthood. Failure to find hypothesized effects on experimenters qualifies these results.