1. Department of Medicine, Division of Preventive Medicine University of Alabama at Birmingham Birmingham AL USA
2. Department of Biostatistics School of Public Health, University of Alabama at Birmingham Birmingham AL USA
3. Department of Medicine University of Arizona Tuscon AZ USA
4. Department of Medicine University of Mississippi Medical Center Jackson MS USA
5. Departments of Public Health and Family Medicine East Carolina University Brody School of Medicine Greenville NC USA
6. Department of Community Health and Epidemiology, Faculty of Medicine Dalhousie University Halifax NS Canada
7. Department of Epidemiology University of Alabama at Birmingham Birmingham AL USA
8. Department of Medicine, Division of General Internal Medicine Weill Medical College of Cornell University New York NY USA