PROSPER partnership delivery system: Effects on adolescent conduct problem behavior outcomes through 6.5 years past baseline.

We report long-term effects of the PROSPER delivery system for universal evidence-based preventive interventions on adolescent conduct problem behaviors (CPBs). A cluster randomized trial included 28 school districts assigned to PROSPER or a control condition. Community-based teams in PROSPER condition school districts selected evidence-based interventions-a family-focused intervention in sixth grade and a school-based intervention the next year; follow-up assessments were conducted through 12th grade. CPBs were measured with 12 self-report items derived from the National Youth Survey. Intervention-control differences were tested via a multi-level Zero-Inflated Poisson (ZIP) model. Differences were significant from 9th through 12th grades; Relative Reduction Rates were between 10.1% and 14.5%. The intervention group was delayed in reaching a 10th grade reference level of CPBs by 10.7 months. Moderation analyses indicated stronger effects for early substance initiators. Findings suggest that the PROSPER delivery system has the potential to reduce CPBs in general populations.

Benefits of universal intervention effects on a youth protective shield 10 years after baseline.

PURPOSE: An earlier randomized controlled study found that a universal, family-focused preventive intervention produced protective shield effects-reduced adolescent exposures to illicit substance opportunities-among adolescents in grade 12. This study examined a follow-up assessment of the sample during young adulthood. METHODS: A randomized controlled trial evaluated the Iowa Strengthening Families Program that was implemented in 22 rural schools (N = 446 families) when the participants were in grade six. Measures included adolescent exposure to illicit substance use and young adult lifetime substance use (age 21; N = 331). Growth curve modeling examined indirect intervention effects through growth factors of adolescent exposure. RESULTS: Findings from this study confirm protective shield effects that mediate long-term reduction of illicit substance use (ß = -.14, p = .02, Relative Reduction Rate = 28.2%). CONCLUSIONS: The benefits of decreasing exposure to substance use during adolescence through universal interventions were supported, with positive effects extending into young adulthood.

Effects of parent-child affective quality during high school years on subsequent substance use.

The literature indicates that the quality of affective relationships between youth and parents is associated with lower levels of a range of problem behaviors during childhood, early and late adolescence. While the protective effect of parental monitoring on substance use in the high school and post high school years has been demonstrated, there is a knowledge gap concerning effects of parent-child affective quality (PCAQ) during the same periods. We tested a conceptual theoretical model to examine the effects of PCAQ on substance use following high school. The sample was from a RCT that assessed adolescents in rural Iowa from the seventh grade through two years after high school (N=456). We specified direct effects of PCAQ in 12th grade on drunkenness, smoking and illicit drug use during the two years immediately following high school graduation. We also specified the effects of early substance use initiation (alcohol, tobacco and marijuana use reported at baseline) on later use. The direct effect of PCAQ in 12th grade on substance use was significant for all substances during at least one of the two years past graduation (ypg). Results were: drunkenness 1 ypg, ß=-.126, p<.05; smoking 1 ypg, ß=-.119, p<.05; 2 ypg, ß=-.146, p<.05; illicit drug use 2 ypg, ß=-.165, p<.05. Some significant indirect effects of PCAQ at baseline, via PCAQ at 12th grade, were found. Results also indicated significant direct effects of early initiation on two of the three substances, albeit with a different pattern of effects over time for each substance by years post high school. Importantly, while early initiation remains the strongest predictor of long-term tobacco and illicit drug use, results show how PCAQ might reduce its harmful effects.