Age period cohort trends in alcohol treatment episodes across Australia from 2003 to 2022.

Abstract

To measure trends in alcohol treatment episodes in Australia, disaggregated by age, period and birth cohort. Age, period, cohort modelling with restricted cubic splines, using Australian alcohol treatment administrative data from July 2002 to June 2022. 1 253 548 closed treatment episodes where alcohol was the primary drug of concern from people aged 10 to 100 years who received treatment for their own substance use in publicly funded specialist alcohol and other drug treatment services. Count of alcohol treatment episodes by age, period, birth cohort and sex. Alcohol treatment episode rates increased over time, peaking in 2022 (330.11 per 100 000 population). Age trends first peaked at around 21 years of age [cross-sectional prevalence = 444.30, 95% confidence interval (CI) = 440.82-447.80; longitudinal prevalence = 462.45, 95% CI = 458.06-466.89], followed by a lifetime peak between 37 and 44 years and declining with older age. Cohorts born from 1974 to 1979 had the highest alcohol treatment episode rates, and the oldest and youngest birth cohorts had the lowest alcohol treatment episode rates. Males were overall 1.8 times as likely as females to have an alcohol treatment episode, but this gap closed with more recent birth cohorts. Alcohol treatment episode rates increased in Australia between 2003 and 2022, and particularly from 2017. Young to middle-aged adults and people born in the 1970s were most at risk, alongside a persistent but narrowing gap between males and females.