[1] Univ Calif San Francisco, Sch Med, Dept Otolaryngol Head & Neck Surg, San Francisco, CA USA
[2] Vet Affairs Puget Sound Hlth Care Syst, Dept Otolaryngol Head & Neck Surg, Seattle, WA USA
[3] Univ Washington, Sch Med, Dept Otolaryngol Head & Neck Surg, Seattle, WA USA
[4] Brockton W Roxbury Vet Affairs Med Ctr, Dept Surg, W Roxbury, MA USA
[5] Harvard Univ, Sch Med, Boston, MA USA
[6] Tenet HealthCare, Dallas, TX USA
[7] Dartmouth Coll, Hitchcock Med Ctr, Dartmouth Med Sch, Dept Community & Family Med, Hanover, NH 03756 USA
[8] Univ Washington, Sch Publ Hlth & Community Med, Dept Hlth Serv, Seattle, WA 98195 USA
[9] Univ Colorado, Hlth Sci Ctr, Colorado Hlth Outcomes Program, Denver, CO USA
[10] Univ Colorado, Hlth Sci Ctr, Dept Prevent Med & Biometr, Denver, CO 80262 USA