1. Department of Emergency Medicine; University of Ottawa; Ottawa Ontario Canada
2. Clinical Epidemiology Program; Ottawa Hospital Research Institute; University of Ottawa; Ottawa Ontario Canada
3. Department of Emergency Medicine; Queen's University; Kingston Ontario Canada
4. Department of Emergency Medicine; University of Alberta; Edmonton Alberta Canada
5. Division of Emergency Medicine; University of Toronto; Toronto Ontario Canada
6. Department of Medicine; University of Ottawa; Ottawa Ontario Canada
7. Division of Emergency Medicine; University of Calgary; Calgary Alberta Canada
8. University of Ottawa Heart Institute; University of Ottawa; Ottawa Ontario Canada