Effects of State Coalitions to Reduce Underage Drinking A National Evaluation Alexander C. Wagenaar, PhD, Darin J. Erickson, PhD, Eileen M. Harwood, PhD, Patrick M. O’Malley, PhD Introduction: Drinking by youth remains prevalent. The Reducing Underage Drinking through coali- tions (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. (Am J Prev Med 2006;31(4):307–315) © 2006 American Journal of Preventive Medicine Introduction A lcohol use among young people contributes to serious social and health problems, such as traffic crashes, increased risk for disease, risky sexual behavior, homicides, suicides, crime, and unin- tentional injury. 1–8 In addition, recent research has shown that exposure to alcohol in adolescence influ- ences brain development, has apparent long-lasting effects on intellectual capabilities, and increases the likelihood of later addiction. 9,10 The relationship be- tween reducing youth access to alcohol and reduced teen drinking and alcohol-related problems is well recognized. Studies show that alcohol-access policies have significant effects on consumption and, subse- quently, on alcohol-related problems, 11–13 apparently via two mechanisms of effect: first, shaping the oppor- tunities and costs for adolescents to drink, and second, shaping normative expectations about appropriate drinking behavior. 14,15 Predominant policy strategies to reduce underage drinking include raising the minimum legal drinking age to 21 in the United States, curtailing commercial access (making it more difficult for youth to buy alcohol at stores and bars), limiting social access (re- ducing older teens giving alcohol to younger teens and reducing adult provision of alcohol to youth), and reducing the economic availability of alcohol (making alcohol more expensive in terms of retail price in relation to disposable income). Raising the legal age for drinking from 18 to 21 in the United States is likely the single most effective prevention measure implemented in the past half- century, resulting in significant declines in teen drink- From the University of Florida Department of Epidemiology and Health Policy Research, College of Medicine (Wagenaar), Gaines- ville, Florida; Department of Epidemiology and Community Health, School of Public Health, University of Minnesota (Erickson, Har- wood), Minneapolis, Minnesota; and Institute for Social Research, University of Michigan (O’Malley), Ann Arbor, Michigan Address correspondence and reprint requests to: Alexander C. Wagenaar, PhD, University of Florida College of Medicine, Depart- ment of Epidemiology and Health Policy Research, P.O. Box 100177, Gainesville FL 32610-0177. E-mail: wagenaar@ufl.edu. 307 Am J Prev Med 2006;31(4) 0749-3797/06/$–see front matter © 2006 American Journal of Preventive Medicine • Published by Elsevier Inc. doi:10.1016/j.amepre.2006.06.001