1. Department of Medical Statistics and Epidemiology, Hamad Medical Corporation and Department of Public Health, Weill Cornell Medical College, Doha, Qatar.
2. Department of Evidence for Population Health Unit, School of Epidemiology and Health Sciences, The University of Manchester, Manchester, UK.
3. Department of Psychiatry, Rumeilah Hospital, Hamad Medical Corporation, Doha, Qatar.
4. Institute of Medical Science, University of Toronto, Clinical Research Rheumatology and Spondyloarthritis Program, Arthritis Centre of Excellence, Toronto Western Hospital, Toronto, ON, Canada.