Research in context
Evidence before this study
We searched PubMed and the China National Knowledge Infrastructure for articles published up to December, 2017, using the terms “chronic obstructive pulmonary disease” or “COPD” and “prevalence” and “China”. We screened papers by reviewing abstracts to identify full-text reports that were relevant to the study aims. The most recent national survey of chronic obstructive pulmonary disease (COPD) in China was done during 2002–04 among 20 245 adults aged 40 years or older and reported an overall prevalence of 8·2% (12·4% in men and 5·1% in women). To the best of our knowledge, no national data for COPD prevalence in Chinese adults younger than 40 years are available.
Added value of this study
Our large, national, cross-sectional study was undertaken in a nationally representative sample of 50 991 adults from the general Chinese population. A post-bronchodilator pulmonary function test was done in all participants to diagnose COPD. Our findings indicate that, in 2015, the spirometry-defined prevalence of COPD was 8·6%, accounting for 99·9 million Chinese adults aged 20 years or older. The prevalence was 13·7% among people aged 40 years or older. For the first time, the prevalence of COPD was reported among the general population aged 20–39 years in China (2·1%). Additionally, our we showed that most people with COPD were unaware of their condition and few had received a previous pulmonary function test. Finally, cigarette smoking and heavy exposure to particulate matter with a diameter less than 2·5 μm were identified as major preventable risk factors for COPD in the Chinese adult population.
Implications of all the available evidence
Spirometry-defined COPD is highly prevalent and increasing in the Chinese adult population. Furthermore, the proportions of people with COPD who are aware of their condition or who have received pulmonary function tests are very low. Moreover, cigarette smoking and air pollution are major preventable risk factors for COPD. Our study calls for new national policy and programmes for the prevention and early detection of COPD. Specifically, health promotion for smoking cessation, control of ambient air pollution and biomass use, and screening for COPD using spirometry in high-risk individuals should be public health priorities.