Joint effect of alcohol consumption and educational level on alcohol-related medical events: A Danish register-based cohort study

BACKGROUND:: Alcohol-related mortality is more pronounced in lower than higher socioeconomic groups in Western countries. Part of the explanation is differences in drinking patterns. However, differences in vulnerability to health consequences of alcohol consumption across socioeconomic groups may also play a role. We investigated the joint effect of alcohol consumption and educational level on the rate of alcohol-related medical events. METHODS:: We pooled seven prospective cohorts from Denmark that enrolled 74 278 men and women aged 30-70 years (study period 1981 to 2009). We measured alcohol consumption at baseline using self-administrated questionnaires. Information on highest attained education one year before study entry and hospital and mortality data on alcohol-related medical events were obtained through linkage to nationwide registries. We performed analyses using the Aalen additive hazards model. RESULTS:: During follow-up (1 085 049 person-years), a total of 1718 alcohol-related events occurred. The joint effect of very high alcohol consumption (>21 (>28) drinks per week in women (men)) and low education on alcohol-related events exceeded the sum of their separate effects. Among men, we observed 289 (95% confidence interval, 123, 457) extra events per 100 000 person-years due to education–alcohol interaction (P <0.001). Similarly, among women we observed 239 (90, 388) extra events per 100 000 person-years due to this interaction (P <0.001). CONCLUSIONS:: High alcohol consumption is associated with a higher risk of alcohol-related medical events among those with low compared to high education. This interaction may be explained by differences in vulnerability and drinking patterns across educational groups. Copyright