Affiliation: | 1. Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia, U.S.A.;2. Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Emory University, Atlanta, Georgia, U.S.A.;3. Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, U.S.A. |