1. Department of Internal Medicine, Hallym University Dongtan Sacred Heart Hospital, Hwaseong-si 18450, Republic of Korea
2. Division of Pulmonology and Critical Care Medicine, Department of Internal Medicine, Chungnam National University College of Medicine, Chungnam National University Sejong Hospital, Sejong 30099, Republic of Korea
3. Division of Pulmonary, Allergy, and Critical Care, Department of Internal Medicine, Inje University Busan Paik Hospital, College of Medicine, Busan 47392, Republic of Korea
4. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chungbuk National University Hospital, Chungbuk National University College of Medicine, Cheongju 28644, Republic of Korea
5. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Sanggye Paik Hospital, Inje University College of Medicine, Seoul 01757, Republic of Korea
6. Division of Allergy, Pulmonary and Critical Care Medicine, Transplant Research Center, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Republic of Korea
7. Department of Internal Medicine, School of Medicine, Pusan National University, Yangsan 46241, Republic of Korea
8. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06974, Republic of Korea
9. Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Konyang University College of Medicine, Daejeon 35365, Republic of Korea
10. Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon 51472, Republic of Korea
11. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Konkuk University School of Medicine, Seoul 05030, Republic of Korea
12. Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea