1. Division of Rheumatology, Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea.
2. Division of Rheumatology, Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
3. Division of Rheumatology, Department of Internal Medicine, Gyeongsang National University Hospital, Jinju, Korea.
4. Division of Rheumatology, Department of Internal Medicine, Kyung Hee University Hospital, School of Medicine, Kyung Hee University, Seoul, Korea.
5. Division of Rheumatology, Department of Internal Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon, Korea.
6. Division of Rheumatology, Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
7. Division of Rheumatology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
8. Division of Rheumatology, Department of Internal Medicine, Konkuk University Medical Center, Seoul, Korea.
9. Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
10. Division of Rheumatology, Department of Internal Medicine, Chonnam National University Medical School & Hospital, Gwangju, Korea.
11. Division of Rheumatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
12. Division of Rheumatology, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
13. Division of Rheumatology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
14. Division of Rheumatology, Department of Internal Medicine, Gyeongsang National University College of Medicine, Jinju, Korea.
15. Division of Rheumatology, Department of Internal Medicine, School of Medicine, Chungnam National University, Chungnam National University Hospital, Daejeon, Korea.
16. Division of Rheumatology, Department of Internal Medicine, Chung-Ang University School of Medicine, Seoul, Korea.