Objective. To investigate an effect of smoking cessation on chronic obstructive pulmonary disease (COPD) mortality in Asians.
Methods. The data was obtained from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). A total of 41465 Japanese men and 52662 Japanese women aged 40-79 years who had no history of COPD, asthma, other chronic lung diseases, cardiovascular disease or cancer were followed between 1988 and 2008.
Results. During median 18-year of follow-up, there were 285 (251 men and 34 women) documented deaths from COPD. Multivariable-adjusted hazard ratios with 95% confidence intervals of COPD death were 4.46 (2.72-7.29) and 9.26 (4.19-20.5), respectively for current male and female smokers when compared to never smokers. Compared with current smokers, the multivariable HRs for 5-9 years and 10 years or more smoking cessation prior to baseline were 0.44 (0.22-0.87) and 0.36 (0.22-0.58) in men, respectively while the HR for never smokers was 0.30(0.16-0.57). There were an insufficient number of COPD deaths in women to clarify this association.
Conclusion. Smoking cessation for ten years or more prior to enrollment reverses the excess risk of COPD mortality to a level similar to that observed among never smokers in men. 2012 Published by Elsevier Inc.