1. University of Iowa Carver College of Medicine, Department of Emergency Medicine, Iowa City, Iowa
2. University of Iowa Carver College of Medicine, Department of Emergency Medicine, Iowa City, Iowa; University of Iowa College of Public Health, Department of Epidemiology, Iowa City, Iowa
3. Northwestern University Feinberg School of Medicine, Department of Emergency Medicine, Chicago, Illinois
4. Northwestern University Feinberg School of Medicine, Department of Emergency Medicine, Chicago, Illinois; Northwestern Medicine and Northwestern University Feinberg School of Medicine, Department of Medicine and Orthopedic Surgery, Chicago, Illinois
5. University of Iowa Carver College of Medicine, Department of Emergency Medicine, Iowa City, Iowa University of Iowa College of Public Health, Department of Epidemiology, Iowa City, Iowa
6. University of Nebraska Medical Center, Department of Emergency Medicine, Omaha, Nebraska
7. University of Iowa Carver College of Medicine, Department of Emergency Medicine, Iowa City, Iowa; Univeristy of Iowa Carver College of Medicine, Department of Orthopedics and Rehabilitation, Iowa City, Iowa
8. University of Iowa Carver College of Medicine, Department of Emergency Medicine, Iowa City, Iowa University of Iowa College of Public Health, Department of Epidemiology, Iowa City, Iowa; University of Iowa Carver College of Medicine, Department of Anesthesia, Division of Critical Care, Iowa City, Iowa