1. Department of Internal Medicine; Seoul National University Bundang Hospital; Seongnam Korea
2. Department of Surgery; Yonsei University College of Medicine; Seoul Korea
3. Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
4. Department of Internal Medicine; Dankook University College of Medicine; Cheonan Korea
5. Department of Surgery; Seoul National University College of Medicine; Seoul Korea
6. Department of Internal Medicine; Seoul National University Hospital; Seoul Korea
7. Department of Otorhinolaryngology-Head and Neck Surgery; Seoul National University College of Medicine; Seoul Korea
8. Department of Internal Medicine; Seoul National University Boramae Medical Center; Seoul Korea
9. Department of Internal Medicine; Chung-Ang University College of Medicine; Seoul Korea