1. From the Departments of Epidemiology (M.L.E., K.M.R.) and Biostatistics (D.J.C.), School of Public Health, University of North Carolina, Chapel Hill; Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis (D.K.A.); Mississippi Family Health Center, Jackson (R.S.); and Division of Hypertension, University of Mississippi Medical Center, Jackson (D.J.).