1. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Hanyang University School of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea.
6. Department of Internal Medicine, Korea University Ansan Hospital, Korea University School of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University School of Medicine, Anyang, Korea.
8. Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea.
9. Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
10. Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
11. Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea.
12. Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
13. Department of Internal Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea.
14. Department of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
15. Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, College of Medicine, Seoul, Korea.
16. Division of Rheumatology, Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea.
17. Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea.
18. Department of Rheumatology, Ajou University School of Medicine, Suwon, Korea.
19. Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
20. Department of Internal Medicine, Chonbuk National University, Medical School, Jeonju, Korea.