1 Department of Respiratory and Critical Care Medicine, Peking University First Hospital, Beijing, China; Department of General Practice, Peking University Health Science Center, Beijing, China.
2 Asthma UK Centre for Applied Research, Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, UK.
3 Department of General Practice, Peking University Health Science Center, Beijing, China; Beijing Xicheng District Xinjiekou Community Health Service Center, Beijing, China.
4 Department of General Practice, Peking University Health Science Center, Beijing, China; Institute of Applied Health Research, University of Birmingham, Birmingham, UK. Electronic address: wangchencardpc@163.com.
5 Department of Respiratory and Critical Care Medicine, China-Japan Friendship Hospital Beijing, China; Department of Respiratory Medicine, Capital Medical University Beijing, China; National Clinical Research Centre for Respiratory Diseases, Beijing, China.