1. Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (K.C.S., B.J.G.)
2. Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota (S.A.W., R.J.)
3. Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, and Epidemiology and Community Health Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland (V.L.R.)
4. Department of Cardiovascular Medicine and Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, Minnesota (P.A.N.)
5. Department of Cardiovascular Medicine and Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota (A.M.C.).