1. Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
2. University of Missouri-Kansas City School of Medicine, Kansas City
3. Department of Mathematics, Washington University School of Medicine in St Louis, St Louis, Missouri
4. Department of Medicine, Washington University in St Louis, St Louis, Missouri
5. Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri