Affiliation: | 1. Beijing Chao‐Yang Hospital, Capital Medical University, Beijing, China;2. Beijing Institute of Respiratory Medicine, Beijing, China;3. World Health Organization Collaborating Center for Tobacco or Health, Beijing, China;4. Department of Respiratory, Capital Medical University, Beijing, China;5. Research Centre of Respiratory Medicine in Beijing Hospital, Ministry of Health of the People's Republic of China, Beijing, China |