1. Einstein Medical Center Philadelphia, Einstein Healthcare Network, Department of Emergency Medicine, Philadelphia, Pennsylvania
2. Baystate Medical Center, University of Massachusetts Medical School-Baystate Health, Department of Emergency Medicine, Springfield, Massachusetts
3. University of Texas Health Science Center Houston, McGovern Medical School, Department of Emergency Medicine, Houston, Texas
4. University of Chicago, Department of Medicine, Biological Sciences Division, Section of Emergency Medicine, Chicago, Illinois
5. Truman Medical Center, University of Missouri-Kansas City School of Medicine, Department of Emergency Medicine, Kansas City, Missouri