1. Department of Emergency Medicine; School of Medicine; Washington University in St. Louis; St. Louis Missouri
2. Becker Medical Library; Washington University in St. Louis; St. Louis Missouri
3. Department of Clinical Epidemiology and Biostatistics; McMaster University; Hamilton Ontario Canada
4. Division of Emergency Medicine; Department of Medicine; McMaster University; Hamilton Ontario Canada
5. School of Medicine; University of Western Ontario School of Medicine; London Ontario Canada
6. School of Medicine; Washington University in St. Louis; St. Louis Missouri