1. From the Divisions of Preventive Medicine (LW, JMG, SL, JEM, JEB, and HDS) and Aging (JMG, JEB, and HDS), Department of Medicine, Brigham and Women's Hospital, Boston, MA; the Department of Epidemiology, Harvard University School of Public Health, Boston, MA (JEM and JEB); and the Department of Epidemiology, University of California at Los Angeles School of Public Health, Los Angeles, CA (SL)