1. From the Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion (M.T.C., H.K.W., C.G., N.K., D.L., Y.H.) Centers for Disease Control and Prevention, Chamblee, GA, and National Center for Health Statistics (S.S.Y., S.S.), Centers for Disease Control and Prevention, Hyattsville, MD; and the National Heart, Lung, and Blood Institute, National Institutes of Health, (E.O., P.S.) Bethesda, MD.