1. Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
2. Department of Epidemiology, University of Iowa College of Public Health, Iowa City, Iowa, USA.
3. Office of Rural Health, Veterans Rural Health Resource Center-Iowa City, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa, USA.
4. Department of Health Management and Policy, University of Iowa College of Public Health, Iowa City, Iowa, USA.
5. Department of Biostatistics, University of Iowa College of Public Health, Iowa City, Iowa, USA.
6. Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
7. Department of Anesthesia, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.