Fifth, results from our younger age groups, in which individuals could be included only if they were born in the earlier years of our cohort and had an early age at first registration, could be biased. We repeated analyses for a cohort born from 1966 to 1990 for which we could define 4 age groups: 15 to 24, 25 to 29, 30 to 39, and 40 to 44 years. Although estimates for the oldest group were very imprecise, we replicated our key finding of decreasing level of confounding of the AUD-mortality association with increasing age (eFigure in the Supplement).
