PROSPER delivery of universal preventive interventions with young adolescents: long-term effects on emerging adult substance misuse and associated risk behaviors

Abstract

BackgroundSubstance misuse and associated health-risking behaviors are prevalent in emerging adulthood. There is a knowledge gap concerning the post-high school effects of community-based delivery systems for universal preventive interventions implemented during young adolescence. This study reports effects of the PROSPER delivery system through age 19, 7.5 years past baseline.MethodsA cohort sequential design included 28 public school districts randomly assigned to the PROSPER partnership delivery system or usual-programming conditions. PROSPER community teams implemented a family-focused intervention in 6th grade and a school-based intervention in 7th grade. Outcomes for the age 19, post-high school report included lifetime, current, and frequency of substance misuse, as well as antisocial and health-risking sexual behaviors. Intent-to-treat, multi-level analyses of covariance of point-in-time outcomes were conducted, along with analyses of risk-related moderation of intervention effects.ResultsResults showed emerging adults from PROSPER communities reported significantly lower substance misuse across a range of types of substances, with relative reduction rates of up to 41.0%. No significant findings were observed for associated antisocial and health-risking sexual behavior indices; or for lifetime rates of sexually transmitted infections. Risk-related moderation effects were non-significant, suggesting generally comparable outcomes across higher- and lower-risk subgroups of emerging adults.ConclusionsThe PROSPER delivery system for brief universal preventive interventions has potential for public health impact by reducing long-term substance misuse, with positive results extending beyond high school.