1. Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
2. Department of Interdepartmental Medicine, Division of Critical Care, University of Toronto, Toronto, Ontario, Canada.
3. Department of Surgery, Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
4. Department of Research and Development, Ornge Transport Medicine and Division of Emergency Medicine, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
5. Department of Emergency Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
6. Department of Emergency Medicine, Surgery and Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia, Canada.