1. Department of Biostatistics and Informatics Colorado School of Public Health Aurora Colorado U.S.A.
2. Department of Otolaryngology University of Colorado Anschutz Medical Campus and Children's Hospital Colorado Aurora Colorado U.S.A.
3. Department of Otolaryngology, Head & Neck Surgery, Division of Pediatric Otolaryngology UT Southwestern and Children's Health Dallas Texas U.S.A.
4. Department of Pediatrics University of Colorado School of Medicine Aurora Colorado U.S.A.