1. Department of Pulmonary & Critical Care Medicine, Chinese People Liberation Army (PLA) General Hospital, Beijing 100853, China.
2. Department of Critical Care Medicine, Peking Union Medical College Hospital, Beijing 100005, China.
3. Department of Pulmonary & Critical Care Medicine, China and Japan Friendship Hospital, Beijing 100029, China.
4. Department of Pulmonary & Critical Care Medicine, Beijing Chaoyang Hospital affiliated to Capital Medical University, Beijing 100020, China.
5. Department of Pulmonary & Critical Care Medicine, Peking University Third Hospital, Beijing 100191, China.
6. Department of Respiratory Medicine, Changhai Hospital, Shanghai 200433, China.
7. Department of Respiratory Medicine, Ruijin Hospital Affiliated to the Shanghai Jiao Tong University Medical School, Shanghai 200025, China.
8. Department of Respiratory Medicine, XiangYa Hospital, Central South University, Changsha, Hunan 410008, China.
9. Department of Pulmonary & Critical Care Medicine, XiangYa Second Hospital of Central South University, Changsha, Hunan 410011, China.
10. Department of Pulmonary & Critical Care Medicine, Xinqiao Hospital of the Third Military Medical University, Chongqing 400037, China.
11. Department of Pulmonary & Critical Care Medicine, Xijing Hospital of Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
12. Department of Respiratory Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830000, China.
13. Department of Pulmonary & Critical Care Medicine, Beijing Hospital, Beijing 100730, China.
14. Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
15. Department of Respiratory Medicine, The First Bethune Hospital of Jilin University, Changchun, Jilin 130021, China.