Objective To examine the prospective associations between airflow obstruction (AFO) and total and cause-specific mortality. Methods The study is based on China Kadoorie Biobank, in which 199 099 men and 287 895 women aged 30 to 79 years at baseline were included after excluding participants with heart disease, stroke, and cancer at baseline. The Global Initiative on Obstructive Lung Disease (GOLD) guideline was used to classify AFO. Cox regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CIs). Results During 3 494 079 person-years of follow-up between 2004 and 2013 (median 7.2 years), a total of 21 649 people died. Absolute mortality rates were 5.5, 9.9, 13.1, 32.4 and 63.3 deaths per 1000 person-years for participants who have normal AFO, GOLD-1 to GOLD-4, respectively. After adjusting potential confounders, compared with participants with normal lung function, the HRs (95% CIs) for death were 0.98 (0.88～1.09), 1.03 (0.97～1.09), 1.62 (1.53～1.73), and 2.83 (2.59～3.10) for those whose AFO were classified as GOLD-1 to GOLD-4, respectively. The airflow obstruction was also associated with increased risk for deaths due to ischemic heart disease, cerebrovascular disease, and chronic obstructive pulmonary disease. Conclusion The airflow obstruction was associated with total and certain cause-specific mortality, independent of other risk factors of death.</p
