From the Tulane Center for Cardiovascular Health (J.K.C., F.M., L.L., L.K., S.R.S., G.S.B.) and the Departments of Epidemiology (J.K.C., F.M., R.S., S.R.S., G.S.B.) and Biostatistics (L.S.W.), Tulane University Medical Center School of Public Health, New Orleans, La, and the Clinical Epidemiology Group (J.K.C.), University of Manchester Medical School, Manchester, England. (At 2005-04-19)