1. Department of Internal Medicine, College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA
2. Medicine, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA
3. Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
4. Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA
5. Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
6. Medicine, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
7. Department of Biostatistics, College of Public Health & Health Professions College of Medicine, University of Florida, Gainesville, FL, USA
8. Department of Surgical Specialties, College of Dentistry, University of Nebraska Medical Center, Lincoln, NE, USA