1. From the Department of Epidemiology, University of Pittsburgh (K.E.K., M.M.B., K.M.D.), Pittsburgh, Pa; Stanford University Medical Center (E.L.A.), Palo Alto, Calif; Montreal Heart Institute (M.G.B.), Montreal, Canada; Toronto General Hospital (L.S.), Toronto, Canada; Mayo Clinic (D.R.H.), Rochester, Minn; Duke Clinical Research Institute (R.M.C.), Durham, NC; Cleveland Clinic Foundation (P.L.W.), Cleveland, Ohio; and St Louis University School of Medicine (B.R.C.), St Louis, Mo.