1 Division of Rheumatology, Department of Internal Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon, Korea.
2 Department of Medicine, Inha University Graduate School, Incheon, Korea.
3 Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
4 Division of Rheumatology, Department of Internal Medicine, Kyung Hee University College of Medicine, Seoul, Korea.
5 Division of Rheumatology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
6 National Health Insurance Service, Wonju, Korea.
7 Division of Rheumatology, Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea.
8 Division of Rheumatology, Department of Internal Medicine, Daegu Catholic University School of Medicine, Daegu, Korea.
9 Division of Rheumatology, Department of Internal Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea.
10 Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Korea.
11 Division of General Internal Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
12 Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
13 Division of Rheumatology, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
14 Department of Rheumatology, Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul, Korea.
15 Division of Rheumatology, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
16 Division of Rheumatology, Daejeon Rheumatoid & Degenerative Arthritis Center, Chungnam National University Hospital, Daejeon, Korea.
17 Korea Ankylosing Spondylitis Society, Seoul, Korea.
18 Korea Ankylosing Spondylitis Corporation, Daejeon, Korea.