1. Critical Care Medicine Department, Peking University Third Hospital, Beijing, China
2. Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing, China
3. Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
4. Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
5. The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China
6. West China Hospital of Sichuan University, Chengdu, Sichuan, China
7. The First Affiliated Hospital of Guangzhou Medical University，Guangzhou Institute of Respiratory Health，Guangzhou，Guangdong， China
8. Beijing Ditan Hospital, Capital Medical University，Chaoyang, Beijing, China
9. The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
10. The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
11. Henan Provincial People's Hospital, Zhengzhou, Henan, China
12. Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong, China
13. Zhejiang Hospital, Hangzhou, China
14. The First Affiliated Hospital, Chongqing Medical University, Chongqing, China
15. Critical Care Medicine Department, Guiqian International General Hospital, Guiyang, Guizhou, China