Forecasting future prevalence and gender differences in binge drinking among young adults through 2040.

Background Binge drinking among adolescents and young adults has changed over time, but patterns differ by age and gender. Identifying high-risk groups to target future efforts at reducing drinking in this population remains a public health priority. Forecasting methods can provide a better understanding of variation and determinants of future binge drinking prevalence. Methods We implemented regression-based forecasting models to estimate the prevalence and gender differences in binge drinking among cohort groups of U.S. young adults, ages 18, 23-24, and 29-30 through 2040. Forecasting models were adjusted for covariates accounting for changes in demographic, Big-5 social roles (e.g., residential independence), and drinking norms and related substance use, to understand the drivers of forecasted binge drinking estimates. Results From the last observed cohort group (years varied by age) through 2040, unadjusted binge drinking prevalence was forecasted to decrease from 26% (95% CI: 20, 33%) (2011-15) to 11% (95% CI: 4, 27%) at age 18, decrease from 38% (95% CI: 30, 45%) (2006-2010) to 34% (95% CI: 18, 55%) at ages 23/24, and increase from 32% (95% CI: 25, 40%) (2001-2005) to 35% (95% CI: 16, 59%) at ages 29/30. Gender-stratified forecasts show a continuation in the narrowing of binge drinking prevalence between young men and women, though the magnitude of narrowing differs by age. Estimated trends were partially explained by changing norms regarding drinking and other substance use, though these indirect effects explained less of the total trend as age increased. Conclusions Understanding how covariates influence binge drinking trends can guide public health policies to leverage the most important determinants of future binge drinking to reduce the harm caused by binge drinking from adolescence to adulthood.