| Institution: | 1. Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, U.S.A;2. Department of Otorhinolaryngology–Head and Neck Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, U.S.A;3. Department of Surgery, University of Arizona, Tucson, AZ, U.S.A;4. Division of Infectious Diseases, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, U.S.A;5. Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, U.S.A |
