title: Tonsillectomy return-to-theatre rates demonstrate a monthly and seasonal variation: an analysis of 256,799 patients.
abstract: OBJECTIVE
  To explore whether the incidence of post-tonsillectomy haemorrhage requiring a return to theatre demonstrates a monthly or seasonal variation.
  
  
  METHODS
  Retrospective, cross-sectional study including all 256 799 tonsillectomies performed between April 2000 and March 2005 in NHS trusts in England.
  
  
  METHODS
  Return-to-theatre rates for each calendar month and each three-month 'season', over the five-year study period.
  
  
  RESULTS
  A statistically significant association was found between the calendar month and the proportion of patients requiring a return to theatre for post-tonsillectomy haemorrhage (p=0.005). There was a bimodal seasonal distribution peaking in the winter and summer months, with winter rates significantly higher than spring rates (p=0.0104).
  
  
  CONCLUSIONS
  The incidence of severe post-tonsillectomy haemorrhage showed monthly and seasonal variations. This is clearly a multi-factorial problem. However, in patients at high risk of bleeding or of the complications of bleeding, consideration should be given to performing tonsillectomy at a time of year of lower incidence.
authors.affiliation: ENT Department, Torbay Hospital, Torquay, UK. neil@chadhanet.com
authors.forename: N K
authors.initials: NK
authors.lastname: Chadha
mesh_terms: D000328:Adult; D002648:Child; D016021:Epidemiologic Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D019106:Postoperative Hemorrhage / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D012086:Reoperation / Q000706:statistics & numerical data; D012621:Seasons; D014068:Tonsillectomy / Q000009:adverse effects*; D006113:United Kingdom / Q000453:epidemiology