1. Department of Otolaryngology–Head and Neck Surgery, Eastern Virginia Medical School, Children’s Hospital of the King’s Daughters, Norfolk, Virginia, USA
2. Department of Otolaryngology, Walter Reed Army Medical Center, Washington, DC, USA
3. Department of Biostatistics, Eastern Virginia Medical School, Norfolk, Virginia, USA
4. Department of Otolaryngology–Head and Neck Surgery, Children’s National Medical Center, Washington, DC, USA