1. Departments of Biostatistics and
2. Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa;
3. Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City VA Medical Center, Iowa City, Iowa; and
4. Epidemiology, College of Public Health, and
5. Clinical Quality, Safety, and Performance Improvement, University of Iowa Hospitals and Clinics, Iowa City, Iowa