1. Department of Otolaryngology-Head & Neck Surgery; University of North Carolina Hospitals; Chapel Hill North Carolina U.S.A
2. Division of Otolaryngology-Head & Neck Surgery; University of California San Diego School of Medicine; San Diego California U.S.A.
3. and the Lineberger Comprehensive Cancer Center Biostatistics Core; University of North Carolina Hospitals; Chapel Hill North Carolina U.S.A