1. Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2. Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea
3. Department of Internal Medicine, Gangneung Asan Hospital, Ulsan University College of Medicine, Gangneung, Korea
4. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
5. Department of Internal Medicine, Daegu Fatima Hospital, Daegu, Korea
6. Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
7. Department of Internal Medicine, Yeungnam University Hospital, Daegu, Korea
8. Department of Internal Medicine, Kwangju Christian Hospital, Gwangju, Korea