1. Division of Pulmonology, Allergy and Critical Care Medicine, Department of Internal Medicine, School of Medicine, Pusan National University and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Republic of Korea
2. VUNO, Seoul 06541, Republic of Korea
3. Department of Internal Medicine, School of Medicine, Pusan National University, Busan 46241, Republic of Korea
4. Department of Critical Care Medicine and Emergency Medicine, Inha University College of Medicine, Incheon 22212, Republic of Korea
5. Division of Biostatistics, Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Republic of Korea
6. Department of Pediatrics, School of Medicine, Pusan National University, Yangsan 50612, Republic of Korea