1. Department of Epidemiology, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
2. School of Population Medicine and Public Health, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
3. The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, Yunnan 650106, China
4. Beijing Centre for Disease Prevention and Control, Beijing 100013, China
5. Department of Respiratory and Critical Care Medicine, Affiliated Hospital of Guilin Medical University, Guilin, Guizhou 561113, China
6. National Clinical Research Center for Respiratory Diseases, China-Japan Friendship Hospital, Beijing 100029, China