1. Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia, US
2. Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, US
3. Atlanta Veterans Affairs Health Care System, Decatur, Georgia, US
4. Vietnam Era Twin Registry, Seattle Epidemiologic Research and Information Center, US Department of Veterans Affairs, Seattle, Washington, US
5. Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, US
6. Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, Georgia, US