1. Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea
2. Department of Internal Medicine, Chungbuk National University Hospital, Chungbuk National University College of Medicine, Cheongju, Korea
3. Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea
4. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
5. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
6. Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
7. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
8. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
9. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
10. Department of Internal Medicine, Center for Thyroid Cancer, National Cancer Center, Goyang, Korea
11. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
12. Daegu Endo Internal Medicine Clinic, Daegu, Korea
13. Department of Medicine and Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
14. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea
15. Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Korea