1. From the Department of Emergency Medicine (I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Clinical Epidemiology Program (L.P.N., D.C.), Ottawa Health Research Institute, University of Ottawa, Ottawa, Canada; Medtronic Emergency Response Systems (R.G.W., F.W.C., P.L.), Redmond, Wash; University of British Columbia and British Columbia Ambulance Service (J.C.) and Vancouver Fire Department (R.B.), Vancouver, Canada; Windsor Base Hospital (P.B.), Windsor, Canada; and Emergency...