1. Women's College Research Institute, Women's College Hospital, Toronto, Ontario, Canada, and Department of Medicine University of Toronto Toronto Ontario Canada
2. Department of Statistics and Actuarial Science University of Waterloo Waterloo Ontario Canada
3. Department of Medicine, University of Toronto, and Schroder Arthritis Institute, Krembil Research Institute Toronto Western Hospital Toronto Ontario Canada
4. Sunnybrook Research Institute, Sunnybrook Hospital, and Institute for Clinical Evaluative Sciences (ICES), and Institute of Health Policy, Management and Evaluation University of Toronto Toronto Ontario Canada
5. Women's College Research Institute, Women's College Hospital, and Department of Medicine, University of Toronto, and ICES, and Institute of Health Policy, Management and Evaluation University of Toronto Toronto Ontario Canada
6. Division of Rheumatology University of Rochester Rochester New York