Joint effect of alcohol drinking and tobacco smoking on all-cause mortality and premature death in China: A cohort study

Background Tobacco smoking and alcohol drinking are associated with several diseases, and studies on the joint effects of smoking and drinking are rare. Objective This study investigates the joint effects of tobacco smoking and alcohol drinking on all-cause and premature mortality in a contemporary cohort. Methods The China Health and Retirement Longitudinal Study (CHARLS) is an ongoing nationally representative survey of subjects aged over 45 years in China that was performed every two years for a total of three waves from 2011 to 2015 in China. We used weighted logistic regression models to estimate the joint effects of tobacco smoking and alcohol drinking on all-cause and premature mortality. Results After adjusting for prespecified confounders, the odds ratios (ORs) of all-cause mortality were 1.51 (95% CI: 1.09-2.10) and 1.47 (95% CI: 1.03-2.08) in smokers and smokers/drinkers, respectively. Compared with nonsmokers/nondrinkers, the OR of smokers/drinkers for premature death was 3.14 (95% CI: 1.56-6.34). In the female subgroup, there was an approximately 5-fold (OR = 4.95; 95% CI: 2.00-12.27) odds of premature mortality for smokers/drinkers compared to nonsmokers/nondrinkers. Conclusion This study found a joint effect of tobacco smoking and alcohol drinking on all-cause and premature mortality among a contemporary and nationally representative cohort in China. Our results suggested that the joint effects were more pronounced in women, but further research is needed.