1 The University of Western Ontario, London, Ontario, Canada.
2 University of Connecticut Health Center Farmington, Connecticut.
3 Northwestern University Feinberg School of Medicine, Chicago, Illinois.
4 University of Ottawa, Ottawa, Canada.
5 Montreal General Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
6 North Shore LIJ Health System, Great Neck, New York.
7 Jewish General Hospital and McGill University, Montreal, Quebec.
8 Hospital General de México Universidad Nacional Autónoma de México, Mexico City, Mexico.
9 Centre Hospitalier de l'Université de Montréal and University of Montreal School of Medicine, Montreal, Quebec, Canada.
10 Istanbul University, Istanbul, Turkey.
11 The Karolinska Institute, Stockholm, Sweden.
12 University of Toronto, University of Toronto Psoriatic Arthritis Program, Centre for Prognosis Studies in the Rheumatic Diseases, University Health Network, Toronto Western Hospital Toronto, Ontario, Canada.
13 University of Queensland, Brisbane, Queensland, Australia.