1. From the Department of Emergency Medicine Rush University Medical Center Chicago IL
2. the Department of Emergency Medicine Brigham and Women's Hospital Boston MA
3. the Department of Emergency Medicine Columbia University Vagelos College of Physicians and Surgeons New York City NY
4. the Department of Emergency Medicine Massachusetts General Hospital Boston MA
5. the Department of Emergency Medicine Northwestern Memorial Hospital Chicago IL
6. the Department of Emergency Medicine Lurie Children's Hospital Chicago IL
7. and the Department of Emergency Medicine University of Utah School of Medicine Salt Lake City UT