1. From the Duke Clinical Research Institute and Departments of Medicine (K.S.P., J.G., R.M.C., R.A.H.) and Genomics and Biostatistics (V.H.), Duke University Medical Center, Durham, NC; Department of Statistics (A.A.T., M.D.), North Carolina State University, Raleigh, NC; Baylor College of Medicine/Texas Medical Center (N.S.K.), Houston, Tex; Erasmus Medical Center (E.B.), Rotterdam, the Netherlands; and the University of Alberta (W-C.C., P.W.A.), Edmonton, Alberta, Canada.