Divergent associations of drinking frequency and binge consumption of alcohol with mortality within the same cohort.

Background Observational studies show beneficial effects of moderate alcohol drinking on all-cause and cardiovascular disease (CVD) mortality, while binge drinking has been linked with increased mortality. The aim of this study was to assess the associations of alcohol use with mortality in a population with a hybrid of drinking patterns. Method Participants in a population based cardiovascular health survey in Finnmark county in 1987-1988, aged 20-62 years, constituted the study cohort. Alcohol use was self-reported by use of questions on frequency of beer, wine and liquor intake, and one question on intake of around five drinks or more per occasion (binge drinking). Information on education, income and use of alcohol in an earlier and in a later survey was linked to the file. Mortality was assessed throughout 2009 by Cox regression, with adjustment for potential confounding factors. In the analysis of mortality by frequency of any alcohol use, we adjusted for binge consumption and vice versa. Results Two opposite trends appeared: a higher all-cause mortality in both sexes, and higher CVD mortality in men, with increasing frequency of binge drinking, compared with non-bingers. Second, in both sexes low-frequent use of any alcohol was associated with lower all-cause and CVD mortality, compared with abstention. The combination of any use of alcohol at least weekly and binge consumption at least monthly was common, particularly in men. Conclusions Questions on drinking frequency and a specific question on binge drinking capture different effects of alcohol use on all-cause and CVD mortality.