Affiliation: | 1. Division of Otolaryngology–Head and Neck Surgery , Intermountain Healthcare, Salt Lake City, Utah, U.S.A;2. Division of Epidemiology , Intermountain Healthcare, Salt Lake City, Utah, U.S.A;3. University of Utah School of Medicine , Salt Lake City, Utah, U.S.A;4. Department of Pediatrics , Intermountain Healthcare, Salt Lake City, Utah, U.S.A;5. Institute for Health Care Delivery Research , Intermountain Healthcare, Salt Lake City, Utah, U.S.A |