1. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
2. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
3. Department of Internal Medicine, Gachon University School of Medicine, Incheon, Korea
4. Department of Internal Medicine, CHA University School of Medicine, Seongnam, Korea
5. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
6. Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
7. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea