1. Richard A. and Susan F. Smith Center for Outcomes Research, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts (M.L., R.W.Y., D.S.K., R.K.W.)
2. Richard A. and Susan F. Smith Center for Outcomes Research, Beth Israel Deaconess Medical Center, and Heart and Vascular Center, Brigham and Women’s Hospital, and Harvard Medical School, Boston, Massachusetts (R.A.)
3. Richard A. and Susan F. Smith Center for Outcomes Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts (Z.Z.)
4. Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri (K.E.J.M.).