1. Center for Access and Delivery Research and Evaluation (CADRE), Iowa City VA Health Care System Iowa City Iowa USA
2. Office of Rural Health, Veterans Rural Health Resource Center, Iowa City VA Health Care System Iowa City Iowa USA
3. Carver College of Medicine, Department of Anesthesia University of Iowa Iowa City Iowa USA
4. Department of Internal Medicine, Carver College of Medicine University of Iowa Iowa City USA
5. College of Public Health, Department of Biostatistics University of Iowa Iowa City Iowa USA