1. Nemours Cardiac Center, A.I. DuPont Hospital for Children, Wilmington, DE (S.S.G.).
2. Department of Preventive Medicine (D.L.-J., N.B.A.), Feinberg Medical School, Northwestern University, Chicago, IL.
3. Department of Internal Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD (J.L., B.A.-V.).
4. Department of Internal Medicine (S.J.S.), Feinberg Medical School, Northwestern University, Chicago, IL.
5. Division of Cardiology, Massachusetts General Hospital, Boston (R.S.).
6. Division of Preventive Medicine, Department of Medicine, University of Alabama at Birmingham (C.E.L.).
7. School of Public Health University of Minnesota, Minneapolis (D.R.J.).