1. Department of Pulmonary and Critical Care Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea
2. Department of Internal Medicine, Konkuk University School of Medicine, Konkuk, Republic of Korea
3. Department of Internal Medicine, Seoul St Mary's Hospital, Catholic University of Korea, Seoul, Republic of Korea
4. Department of Internal Medicine, Yeouido St Mary's Hospital, Catholic University of Korea, Seoul, Republic of Korea
5. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
6. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea
7. Department of Internal Medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
8. Department of Clinical Research Support, National Strategic Coordinating Center for Clinical Research, Seoul, Republic of Korea
9. Department of Nursing, College of Medicine, Chosun University, Gwangju, Republic of Korea