1 Department of Emergency Medicine, Faculty of Medicine &Dentistry, University of Alberta, 1G1.43WMC 8440-112 Street NW, Edmonton, AB, T6G 2B7, Canada.
2 J.W. Scott Health Sciences Library, University of Alberta, 2K3.28 Walter C. Mackenzie Health Sciences Centre 8440-112 Street NW, Edmonton, AB, T6G 2R7, Canada.
3 Department of Emergency Medicine, Faculty of Medicine &Dentistry, University of Alberta, 1G1.43WMC 8440-112 Street NW, Edmonton, AB, T6G 2B7, Canada. brian.rowe@ualberta.ca.
4 School of Public Health, University of Alberta, Edmonton, AB, Canada. brian.rowe@ualberta.ca.