Smoking After Age 65 Years and Mortality: The Kangwha Cohort Study

Background: The relationship between smoking and mortality in elderly people, especially in women, is unclear. The present paper examines the association between smoking and the risk of mortality due to all causes of death with a special focus on cardiovascular disease in elderly Korean men and women. Methods: This study followed a cohort of 2201 residents (934 males and 1267 females) in Kangwha county who were ≥ 65 years of age. All patients were followed from March 1994 through December 31, 2005 (11.8 years) in order to determine cause-specific mortality. We calculated the hazard ratio of mortality according to smoking status using the Cox proportional hazard model. Results: During the 11.8 years of the study duration, 529 men and 498 women died. Current female smokers also demonstrated higher levels of cognitive impairment than nonsmokers. Current female smokers demonstrated significantly increased risks of mortality from deaths due to all causes and total cardiovascular disease in comparison with female nonsmokers. The hazard ratio (95% confidence interval) of mortality was 1.32 (1.05–1.66) for all causes and 1.76 (1.10–2.82) for total cardiovascular disease. Current male smokers also demonstrated an increased risk of mortality due to all causes in comparison with male nonsmokers, but this outcome was not statistically significant. Conclusion: The results of this study suggest that smoking has a harmful effect on the risk of mortality due to cardiovascular diseases in elderly Korean women. However, these findings need to be confirmed by further studies.