1. Department of Emergency Medicine, University of British Columbia Department of Emergency Medicine, Vancouver General Hospital Vancouver British Columbia Canada
2. Department of Emergency Medicine University of British Columbia Vancouver British Columbia Canada
3. Department of Family Practice University of British Columbia Vancouver British Columbia Canada
4. Institute for Clinical Evaluative Sciences Department of Medicine University of Toronto Toronto Ontario Canada
5. Department of Emergency Medicine University of Alberta Edmonton Alberta Canada
6. Department of Emergency Medicine Emergency Strategic Clinical Networ, Alberta Health Services University of Alberta Edmonton Alberta Canada
7. Patients for Patient Safety Canada Roberts Creek Vancouver British Columbia Canada
8. Population Data BC School of Population and Public Health, University of British Columbia Vancouver British Columbia Canada