Objective: This study sought to discover recent age-specific and cohort-specific patterns of newly incident drinking of alcoholic beverages among young people in the United States, with identification of age at peak risk, cohort by cohort, and age by age.
Method: Data are from the U.S. National Surveys on Drug Use and Health 2002-2013, with 12 independent successive replications of nationally representative surveys (n ≈ 420,000 12- to 25-year-olds). Drinking was assessed via confidential computer-assisted self-interviews.
Results: Looking across age strata, we found rising age-specific drinking incidence rates across adolescence to a plateau at age 16-18 years and made a new discovery of a statistically robust and highly reproducible dip in incidence at age 19-20 years, followed by the major peak at age 21 years, with sharply reduced incidence thereafter. Evaluated using an epidemiological mutoscope view, individual cohorts showed a congruent pattern, with starting age held constant. A completely different pattern was seen in age-specific prevalence estimates that showed monotonic linear increases.
Conclusions: The novelty seen here, with multiple replications, is a set of clearly nonlinear, age-specific drinking incidence patterns not documented in prior studies. Evidence of noncongruent prevalence patterns is provided. We hope these simple examples will be useful in teaching the epidemiology of alcohol drinking.