Understanding trends in Australian alcohol consumption-an age-period-cohort model

Aims: To decompose Australian trends in alcohol consumption into their age, period (survey year) and cohort (birth year/generation) components. In particular, we aimed to test whether recent declines in overall consumption have been influenced by reductions in drinking among recently born cohorts. Design: Seven cross-sectional waves of the Australian National Drug Strategy Household Survey (1995-2013). Age, period and cohort effects were estimated using a linear and logistic cross-classified random-effects models (CCREMs). Setting: Australia Participants: A total of 124440 Australians (69193 females and 55257 males), aged 14-79years. Measurements: Whether or not respondents consumed alcohol in the 12months prior to the survey and, for those who did, the estimated volume of pure alcohol consumed, derived using standard quantity-frequency survey questions. Findings: Controlling for age and period effects, there was significant variation in drinking participation and drinking volume by birth cohort. In particular, male cohorts born between the 1965 and 1974 and female cohorts born between 1955 and 1974 reported higher rates of drinking participation (P<0.05), while the most recent cohorts (born in the 1990s) had lower rates of participation (P<0.01). Among drinkers, the most recently born cohort also had sharply lower average consumption volumes than older cohorts for both men and women (P<0.01). Conclusion: Recent birth cohorts (born between 1995 and 1999) in Australia report significantly lower rates of both drinking participation and drinking volume than previous cohorts, controlling for their age distribution and overall changes in population drinking. These findings suggest that the recent decline in alcohol consumption in Australia has been driven by declines in drinking among these recently born cohorts. These trends are consistent with international shifts in youth drinking.