1. From the Department of Preventive Medicine (M.R.C.) and Division of General Internal Medicine, Department of Medicine (N.S.E.), Feinberg School of Medicine, Northwestern University, Chicago, Ill; Preventive Medicine Research Laboratory (T.S.C.), Pennington Biomedical Research Center, Baton Rouge, La; Division of Preventive Medicine (C.E.L.), Department of Medicine, University of Alabama Birmingham, Birmingham, Ala; Division of Epidemiology and Community Health (P.J.S., D.R.J.), School of Public...