State alcohol policies, taxes, and availability as predictors of adolescent binge drinking trajectories into early adulthood.

Abstract

A number of alcohol policies in the United States have been presumed to reduce underage youth drinking. This study characterized underage youth binge-drinking trajectories into early adulthood and tested associations with the strength of the alcohol policy environment, beer excise taxes and number of liquor stores. Longitudinal cohort study. United States. A national cohort of 10th graders in 2010 (n=2753), assessed annually from 2010 to 2015. Participants reported on their 30-day binge drinking [defined as consuming five or more+ (for boys) or four or more (for girls) drinks within 2hours]. We scored the strength of 19 state-level policies at baseline and summarized them into an overall score and two subdomain scores. We also assessed state beer excise taxes (dollars/gallon) and linked the number of liquor stores in 1km to the participants' geocoded address. We identified five binge-drinking trajectories: low-risk (32.9%), escalating (26.1%), late-onset (13.8%), chronic (15.1%) and decreasing (12.0%). Lower overall alcohol policy strength was associated with increased risk of being in the escalating versus low-risk binge-drinking class [relative risk ratio (RRR)=1.44 per 1 standard deviation (SD) in policy score; 95% confidence interval (CI)=1.17, 1.77)]. Higher beer excise taxes were associated with a reduced risk of being in the escalating class (RRR=0.22 per 1-dollar increase; 95% CI=0.09, 0.50). The number of liquor stores was not significantly associated with any binge-drinking trajectory. In the United States, stronger state alcohol policies and higher beer excise taxes appear to be associated with lower risk of escalating alcohol consumption trajectories among underage youth.