1. Department of Medicine, Washington DC Veterans Affairs Medical Center, Washington, DC, USA
2. Department of Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
3. Department of Medicine, Georgetown University School of Medicine, Washington, DC, USA
4. College of Arts and Sciences, American University, Washington, DC, USA
5. College of Computer, Math and Natural Sciences, University of Maryland, College Park, MD, USA
6. Department of Health Administration and Policy, George Mason University, Fairfax, VA, USA
7. Division of Cardiology, Cook County Health and Hospitals System, Chicago, IL, USA
8. Division of Cardiology, Rush University Medical Center, Chicago, IL, USA
9. Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA