1 Department of Emergency Medicine, Clinical Epidemiology Unit, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada. alexandra.hamelin@albertahealthservices.ca.
2 Department of Emergency Medicine, University of Calgary, Calgary, AB, Canada. alexandra.hamelin@albertahealthservices.ca.
3 Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, ON, Canada.
4 Department of Emergency Medicine, Clinical Epidemiology Unit, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada.