1. Department of Immunology and Rheumatology Nagasaki University Graduate School of Biomedical Sciences Nagasaki Japan
2. Department of Island and Community Medicine Nagasaki University Graduate School of Biomedical Sciences Nagasaki Japan
3. Kyushu Multicenter Rheumatoid Arthritis Ultrasound Prospective Observational Cohort Study Group Nagasaki Japan
4. Department of General Medicine Nagasaki University Graduate School of Biomedical Sciences Nagasaki Japan
5. Center for Collaborative Medical Education and Development Nagasaki University Institute of Biomedical Sciences Nagasaki Japan