1. University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
2. Wisconsin Surgical Outcomes Research Program, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
3. Division of Otolaryngology-Head & Neck Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
4. Division of Endocrine Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.