1. Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
2. Division of Epidemiology and Public Health, University of Nottingham, Nottingham, England
3. Arthritis Research UK Primary Care Centre, Keele University, Keele, England
4. Division of Rheumatology, Orthopaedics and Dermatology, University of Nottingham, Nottingham, England