1. From the Preventive Medicine Residency, Department of Social Medicine (C.D.J.), and Departments of Epidemiology (C.D.J., L.L., N.F., W.D.R., K.M.R.), Cardiology (P.P.C.), and Biostatistics (D.J.C.), University of North Carolina at Chapel Hill, Chapel Hill, NC; Division of Epidemiology and Biostatistics (E.S.), University of Arizona, Tucson, AZ; SRA International, Inc (K.M.R.), Durham, NC.