1. Division of Otolaryngology–Head & Neck Surgery, Department of Surgery, University of Utah, Salt Lake City
2. Comparative Effectiveness, Cost and Outcomes Research Center, University of Washington, Seattle
3. Division of Occupational and Environmental Medicine, Department of Medicine, University of California, San Francisco
4. Department of Otolaryngology–Head and Neck Surgery, University of Washington, Seattle
5. Surgery Service, Seattle VA Medical Center, Seattle, Washington