1. Department of Otolaryngology Emory University School of Medicine Atlanta Georgia U.S.A.
2. Department of Otolaryngology‐Head and Neck Surgery Southern California Permanente Medical Group San Diego California U.S.A.
3. Division of Otolaryngology‐Head and Neck Surgery University of Montreal Montreal Quebec Canada
4. Department of Otolaryngology‐Head and Neck Surgery Southern California Permanente Medical Group Los Angeles California U.S.A.
5. Department of Biostatistics and Bioinformatics Emory University Rollins School of Public Health Atlanta Georgia U.S.A.
6. Department of Neurosurgery Southern California Kaiser Permanente Medical Group San Diego California U.S.A.