1. Vanderbilt Voice Center, Department of Otolaryngology, Vanderbilt University Medical Center, Nashville, Tennessee
2. Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
3. Saint Louis University School of Medicine, St Louis, Missouri
4. Vanderbilt University, Nashville, Tennessee
5. Otolaryngology, Department of Surgery, Wisconsin Surgical Outcomes Research, University of Wisconsin, Madison