1. Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois2Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
2. Division of Intramural Research, National Institute on Aging, Baltimore, Maryland
3. Department of Health Research and Policy, Stanford University, Stanford, California
4. Department of Epidemiology, University of Maryland, Baltimore
5. Department of Surgery, University of North Carolina, Chapel Hill
6. Department of Medicine, University of Chicago, Chicago, Illinois
7. Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
8. Department of Medicine, University of Wisconsin, Madison
9. Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
10. Texas Heart Institute, Houston
11. Department of Surgery, University of Chicago, Chicago, Illinois
12. Department of Surgery, Northwestern University, Chicago, Illinois12Jesse Brown VA Medical Center, Chicago, Illinois
13. Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
14. Department of Family and Preventive Medicine, University of California at San Diego, La Jolla