Effects of state coalitions to reduce underage drinking - A national evaluation

Introduction: Drinking by youth remains prevalent. The Reducing Underage Drinking through coalitions (RUD) project funded ten states for 8 years to form coalitions designed to change the policy and normative environment regarding youth access to alcohol. An independent national outcome evaluation of this $21-million effort was conducted.

Methods: Using a longitudinal quasi-experimental design, the ten intervention states were compared with the other 40 states, with repeated annual measures of outcomes from 1995 to 2004. Measures included print news media coverage, legislative bills enacted, youth drinking behavior, and youth alcohol-related driving behaviors and traffic crash mortality. Analyses using latent growth curve modeling methods were conducted in 2005.

Results: Significant differences in slopes between treatment and comparison states were found for several outcome measures, particularly in the more-proximal outcome domains. Across all outcome domains, the pattern of effects was in the direction of positive effects of the RUD coalitions, although for most individual measures the differences were not statistically significant. The magnitude of observed differences associated with the RUD coalitions were sizable, with an estimated effect size of 1.10 on media coverage, 0.46 on state policies enacted, -0.44 on youth drinking behaviors, and -0.16 on alcohol-related driving and fatal car-crash mortality.

Conclusions: The pattern of results and the magnitude of estimated effects provides evidence of effect of the RUD coalitions. The lack of statistically significant differences for most individual outcome measures indicates the difficulty of unambiguously demonstrating the full effects of an effort designed to change behaviors and health outcomes of the entire youth population of multiple states.