1. Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
2. Section of Otolaryngology, Department of Surgery, Department of Veterans Affairs Medical Center, White River Junction, Vermont.
3. Section of Otolaryngology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire.
4. VA Outcomes Group, Department of Veterans Affairs Medical Center, White River Junction, Vermont.
5. The Dartmouth Institute for Health Policy and Clinical Practice, Hanover, New Hampshire.