1. From the Division of Preventive Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (N.R.C.); Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins School of Medicine, Baltimore, MD (L.J.A.); and Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA (P.K.W.).