Time trends in heavy drinking among middle-aged and older adults in Denmark

Background: Studies have indicated an increasing proportion of heavy drinking among middle-aged and older Danes. Trends in consumption are often extremely sensitive to influence from various components of the time trends but only few have explored the age, period and cohort-related influences on late life alcohol consumption. By using age, period, and cohort modeling this study explores the time trends in heavy drinking. Methods: Data derive from five National Health and Morbidity Surveys conducted by the Danish National Institute of Public Health in 1987, 1994, 2000, 2003, and 2005. A total of 15,144 randomly selected Danes between the age of 50 and 74 were interviewed about their alcohol intake on the last weekday and their alcohol intake in the last week. By applying the age-period-cohort model the probability of heavy alcohol drinking is estimated to separate the influence of age, period (calendar time) and cohort (year of birth). Results: The unadjusted probability of heavy drinking declines by age and increases by calendar year and year of birth for both men and women. However, the negative effect of age is attenuated for women when adjusted for birth cohort, indicating that the proportion of heavy drinking women increases in younger birth cohorts. This trend is not observed for men as their drinking pattern mainly increase slightly by calendar year. Conclusions: Our Danish observations for older aged individuals correspond to the social and cultural changes in the 1960s and 1970s that possibly have affected the drinking behavior of the cohorts. Time trend analyses, such as this may serve as an excellent opportunity to extrapolate and forecast alcohol mortality and morbidity.