1. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
2. Medical Research Project Team, IM Medical, Pfizer Korea Pharmaceuticals Limited Company, Seoul, Korea.
3. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. Division of Biostatistics, Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, Korea.
5. Division of Acute Care Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
6. Department of Trauma and Surgical Critical Care and Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
7. Department of Intensive Care Medicine, Dong-A University Hospital, Busan, Korea.
8. Department of Surgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
9. Department of Thoracic & Cardiovascular Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
10. Department of Critical Care Medicine, Internal Medicine, Seoul National University Hospital, Seoul, Korea.
11. Department of Critical Care Medicine, Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Korea.
12. Department of Acute Care Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
13. Department of Thoracic and Cardiovascular Surgery, Keimyung University School of Medicine, Daegu, Korea.
14. Division of Pulmonology and Allergy, Department of Internal Medicine, Regional Center for Respiratory Diseases, Yeungnam University Medical Center, College of Medicine, Yeungnam University, Daegu, Korea.
15. Department of Thoracic and Cardiovascular Surgery, Yeungnam University Medical Center, College of Medicine, Yeungnam University, Daegu, Korea.
16. Division of Critical Care Medicine, Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
17. Department of Internal Medicine, Daegu Catholic University Medical Center, Daegu Catholic University School of Medicine, Daegu, Korea.
18. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
19. Department of Critical Care Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
20. Department of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Hwaseong, Korea.
21. Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
22. Department of Pulmonary, Allergy, and Critical Care Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
23. Division of Acute Care Surgery, Department of Surgery, Korea University Guro Hospital, Seoul, Korea.
24. Department of Internal Medicine, Inje University Haeundae Paik Hospital, Busan, Korea.
25. Division of Pulmonology and Critical Care Medicine, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
26. Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Korea.
27. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
28. Department of Emergency Medicine, Gachon University Gil Medical Center, Incheon, Korea.
29. Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea.
30. Division of Acute Care Surgery, Department of Surgery, Hallym University Sacred Heart Hospital, Anyang, Korea.
31. Department of Emergency Medicine, Ajou University School of Medicine, Suwon, Korea.
32. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.