1. Monash Department of Clinical Epidemiology, Cabrini Institute, 183 Wattletree Road, Malvern, VIC 3144, Australia
2. Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, VIC 3004, Australia
3. Austin Spondylitis Clinic, Austin Health, Studley Road, Heidelberg, VIC 3084, Australia
4. Centre of Clinical Research Excellence in Therapeutics, Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, VIC 3800, Australia
5. School of Physiotherapy, Curtin University of Technology, WA 6000, Australia
6. Department of Rheumatology, St George Hospital, NSW 2217, Australia
7. Department of Rheumatology, Royal North Shore Hospital, NSW 2065, Australia
8. Institute of Bone and Joint Research, University of Sydney, NSW 2065, Australia