1. Department of Surgery, University of Wisconsin—Madison, Madison, Wisconsin, USA.
2. Wisconsin Surgical Outcomes Research, University of Wisconsin—Madison, Madison, Wisconsin, USA.
3. Division of Endocrine Surgery, Department of Surgery, University of Wisconsin—Madison, Madison, Wisconsin, USA.
4. Section of Otolaryngology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
5. The VA Outcomes Group, US Department of Veterans Affairs Medical Center, Windsor County, Vermont, USA.
6. Division of Otolaryngology, Department of Surgery, University of Wisconsin—Madison, Madison, Wisconsin, USA.