1. Department of Otolaryngology Head and Neck Surgery; Nashville Tennessee
2. Division of Epidemiology, Department of Medicine; Nashville Tennessee
3. Veteran's Affairs Geriatric Research Education Clinical Center for Tennessee Valley; Nashville Tennessee
4. Division of Pulmonary and Critical Care, Department of Medicine ; Vanderbilt University Medical Center; Nashville Tennessee
5. Division of Otolaryngology, Department of Surgery ; University of Wisconsin School of Medicine and Public Health; Madison Wisconsin U.S.A.