1. University of Toronto, Centre for Prognosis Studies in The Rheumatic Diseases, Toronto Western Hospital, Toronto, Ontario, Canada; Centre for Prognosis Studies in The Rheumatic Diseases, University Health Network, Toronto Western Hospital, 399 Bathurst Street 1-318, Toronto, Ontario, M52 2S8, Canada; Tel: (+1) 416 603 5753; Fax: (+1) 416 603 9387
2. University of Toronto, Toronto, Ontario, Canada