Impact of smoking and smoking cessation on lung cancer mortality in the Asia-Pacific region

American Journal of Epidemiology Copyright © 2007 by the Johns Hopkins Bloomberg School of Public HealthCigarette smoking is becoming increasingly common in Asia while quitting remains rare, in part because of a lack of knowledge about the risks of smoking. This study compared the risk of death from lung cancer associated with smoking habits in Australia and New Zealand and in Asia by using data from the Asia Pacific Cohort Studies Collaboration: 31 studies involving 480,125 individuals. Cox regression models were used. The hazard ratios for lung cancer mortality associated with current smoking were, for men, 2.48 (95% confidence interval (CI): 1.99, 3.11) in Asia versus 9.87 (95% CI: 6.04, 16.12) in Australia and New Zealand; p for homogeneity <0.0001. For women, the corresponding estimates were 2.35 (95% CI: 1.29, 4.28) in Asia versus 19.33 (95% CI: 10.0, 37.3) in Australia and New Zealand; p for homogeneity