1. From the Departments of Medicine (M.S.B., M.G.S., W.S.B., N.B.S., M.A.W.) and Epidemiology and Biostatistics (M.G.S., W.S.B., M.A.W.) and the Division of Cardiology (N.B.S.), University of California, San Francisco; the Section of General Internal Medicine, VA Medical Center (M.G.S., H.L., M.A.W.); and Research Institute, California Pacific Medical Center (W.S.B.), San Francisco.