The importance of age groups in estimates of alcohol-attributable mortality: impact on trends in Switzerland between 1997 and 2011 (2016)

Background and Aims: Monitoring trends of alcohol-attributable mortality is an integral part of the global strategy to reduce the harmful use of alcohol. However, mortality estimates based on different age ranges come to different conclusions. This study examined the impact of including different age ranges in terms of directions of trends of alcohol-attributable mortality during 14 years in Switzerland.
Method: Alcohol-attributable mortality was estimated at four time-points between 1997 and 2011 using the Global Burden of Disease 2010 methodology. Estimates were obtained for two age groups: 15-64 years and the total adult population (15 years and older).
Results: Alcohol-attributable mortality among 15-64-year-olds decreased [1997: 1334 deaths, confidence interval (CI) = 1237-1432; 2011: 1019 deaths, CI = 964-1073; trend per year odds ratio (OR) = 0.99, P<0.001]. In contrast, alcohol-attributable mortality among those 65 and older increased in the same time-period (1997: 581 deaths, CI = -196 to 1357; 2011: 1664 deaths, CI = 957-2372; OR = 1.07, P<0.001), resulting in an overall increase of alcohol-attributable mortality for 15+ year-olds (1997: 1915 deaths, CI = 1133-2697; 2011: 2683, CI = 1973-3393; OR = 1.02, P<0.001). The main shift in trends was due to changes in the mixture (e.g. hypertension, ischaemic heart disease) of cardiovascular diseases over time among those 65+ years old.
Conclusions Trends in alcohol-attributable mortality may yield qualitatively different results based on the upper age limit for deaths set for these estimates. Global trends of alcohol-attributable mortality between 1997 and 2011 were influenced heavily by changes in the mixture of deaths across cardiovascular diseases. Trends for alcohol-attributable mortality and cross-country comparisons should be reported separately for 15-64 and 65+ year-olds.