1. Renal-Electrolyte and Hypertension Division (J.B.C., R.R.T.), Perelman School of Medicine, University of Pennsylvania, Philadelphia.
2. Department of Biostatistics, Epidemiology, and Informatics (J.B.C.), Perelman School of Medicine, University of Pennsylvania, Philadelphia.
3. Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.).
4. Department of Epidemiology and Biostatistics, School of Public Health, MRC Centre for Environment and Health, Imperial College London, United Kingdom (D.G.).
5. Medical Research Council Biostatistics Unit, School of Clinical Medicine (S.B.), University of Cambridge, United Kingdom.
6. Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care (S.B.), University of Cambridge, United Kingdom.
7. Department of Medicine, Case Western University, University Hospitals Case Medical Center, Cleveland, OH (M.R.).
8. Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City (T.C.H.).
9. Department of Medicine, Boston University School of Medicine, MA (V.S.R.).
10. Department of Epidemiology, Boston University School of Public Health, MA (V.S.R.).
11. Framingham Heart Study, Framingham, MA (V.S.R., K.M.M.).
12. Division of Cardiology (J.A.C.), Perelman School of Medicine, University of Pennsylvania, Philadelphia.