1. From the National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Ga (M.D., W.H.G., S.R.D., D.P.C., R.F.A.); the Department of Preventive Medicine, Southern California Permanente Medical Group (Kaiser Permanente), San Diego, Calif (V.J.F.); and the Department of Neurology, Emory University, Atlanta, Ga (J.E.W.).