1. Department of Medicine, Division of Emergency Medicine McMaster University Hamilton Ontario Canada
2. Department of Medicine, Division of Critical Care McMaster University Hamilton Ontario Canada
3. Department of Health Research Methods, Evidence and Impact McMaster University Hamilton Ontario Canada
4. Department of Emergency Medicine University of Maryland Upper Chesapeake Medical Center Bel Air Maryland USA
5. Department of Emergency Medicine University of Maryland School of Medicine Baltimore Maryland USA
6. Division of Otolaryngology–Head & Neck Surgery Beth Israel Deaconess Medical Center, Harvard Medical School Boston Massachusetts USA
7. Department of Emergency Medicine Beth Israel Deaconess Medical Center Boston Massachusetts USA
8. Department of Emergency Medicine Harvard Medical School Boston Massachusetts USA