title: Rates and risk factors for subsequent tonsillectomy after prior adenoidectomy: a regression analysis.
abstract: OBJECTIVE
  To determine the role of adenoidectomy without concurrent tonsillectomy in the treatment of upper airway obstruction, by determining rates and risk factors for subsequent tonsillectomy.
  
  
  METHODS
  Retrospective cohort study with nested case-control study. Data were evaluated using Kaplan-Meyer curves with Cox proportional hazards regression analysis, as well as contingency table and logistic regression analysis.
  
  
  METHODS
  Tertiary care pediatric hospital with satellite clinics and surgical centers.
  
  
  METHODS
  A total of 2462 patients aged 5 months to 18 years undergoing adenoidectomy without concurrent tonsillectomy.
  
  
  METHODS
  A 5-year database was searched for birth dates, dates of initial surgery, and dates of subsequent tonsillectomy (if performed) or latest follow-up. Cases (tonsillectomies) were then matched 1:1 by age with controls (no subsequent tonsillectomy). Medical charts were reviewed to identify potential predisposing factors, including sex, tonsil size, and adenoidectomy or tonsillectomy indication.
  
  
  RESULTS
  Within 5.4 years, 108 patients underwent subsequent tonsillectomy. The relative risk of subsequent tonsillectomy decreases by 0.83 (95% confidence interval, 0.78-0.88) for each increasing year of age at adenoidectomy. The odds of undergoing a future tonsillectomy significantly increase with increasing tonsil size at the time of adenoidectomy. There was a trend toward doubling the risk of subsequent tonsillectomy when the adenoids were removed for upper airway obstruction (including obstructive sleep apnea) compared with other indications (P = .06).
  
  
  CONCLUSIONS
  Knowledge of the rates and risk factors for subsequent tonsillectomy will allow more informed counseling of parents regarding whether tonsillectomy should be performed or deferred at the time of an indicated adenoidectomy.
authors.affiliation: Center for Pediatric ENT-Head and Neck Surgery, Boynton Beach, FL 33437, USA. davidkay@pol.net
authors.forename: David J
authors.initials: DJ
authors.lastname: Kay
authors.forename: Paul C
authors.initials: PC
authors.lastname: Bryson
authors.forename: Margaretha
authors.initials: M
authors.lastname: Casselbrant
mesh_terms: D000233:Adenoidectomy / Q000379:methods / Q000706:statistics & numerical data*; D017677:Age Distribution; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D016015:Logistic Models; D008297:Male; D016016:Proportional Hazards Models; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D014068:Tonsillectomy / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome