title: Tonsillectomy and the risk for deep neck infection-a nationwide cohort study.
abstract: BACKGROUND
  Although the tonsils contribute to first line immunity against foreign pathogens in the upper aero-digestive tract, the association of tonsillectomy with the risk of deep neck infection remains unclear. The aim of this study was to assess the incidence rate and risk of deep neck infection among patients who had undergone a tonsillectomy.
  
  
  METHODS
  This retrospective cohort study evaluated all patients who had undergone tonsillectomy between 2001 and 2009 as identified from the Taiwan National Health Insurance Research Database. For each post-tonsillectomy patient, 10 age-, sex-, and index date-matched controls without a history of tonsillectomy were randomly selected. Cox Proportional hazard model and propensity score model were performed to evaluate the association between tonsillectomy and deep neck infection after adjusting for demographic and clinical data.
  
  
  RESULTS
  There were 34 (71.6 cases per 100,000 person-years) and 174 (36.6 cases per 100,000 person-years) patients that developed deep neck infection in the tonsillectomized and comparison cohorts, respectively. After adjusting for covariates, patients who had undergone a tonsillectomy had a 1.71-fold greater risk of deep neck infection by both Cox proportional hazard model (95% confidence interval, 1.13-2.59) and propensity score model (95% confidence interval, 1.10-2.66). This association was not altered regardless of the indication for tonsillectomy (i.e. chronic/recurrent tonsillitis or sleep apnea/hypertrophy of tonsil) (p = 0.9797).
  
  
  CONCLUSIONS
  Based on our review of a nationwide cohort study we identified that the risk of deep neck infection is significantly increased among patients who have undergone a tonsillectomy. Additional research is needed to explore the possible mechanisms behind these findings.
authors: Department of Otolaryngology-Head and Neck Surgery, Mackay Memorial Hospital, #92, Sec. 2, Zhongshan N. Rd., Zhongshan Dist., Taipei 104, Taiwan; Institute of Public Health and Community Medicine Research Center, National Yang-Ming University, #155, Sec. 2, Linoon Street, Pei-Tou Dist., Taipei 112, Taiwan; Department of Audiology and Speech Language Pathology and School of Medicine, Mackay Medical College, #46, Sec. 3, Zhongzheng Rd., Sanzhi Dist., New Taipei City 252, Taiwan.
authors: Ying-Piao
authors: YP
authors: Wang
authors: Institute of Public Health and Community Medicine Research Center, National Yang-Ming University, #155, Sec. 2, Linoon Street, Pei-Tou Dist., Taipei 112, Taiwan; Department of Otolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, #201, Sec. 2 and School of Medicine, National Yang-Ming University, #155, Sec.2, Linoon Street, Pei-Tou Dist., Taipei 112, Taiwan.
authors: Mao-Che
authors: MC
authors: Wang
authors: Department of Otolaryngology-Head and Neck Surgery, Mackay Memorial Hospital, #92, Sec. 2, Zhongshan N. Rd., Zhongshan Dist., Taipei 104, Taiwan; Department of Audiology and Speech Language Pathology and School of Medicine, Mackay Medical College, #46, Sec. 3, Zhongzheng Rd., Sanzhi Dist., New Taipei City 252, Taiwan.
authors: Hung-Ching
authors: HC
authors: Lin
authors: Department of Otolaryngology-Head and Neck Surgery, Mackay Memorial Hospital, #92, Sec. 2, Zhongshan N. Rd., Zhongshan Dist., Taipei 104, Taiwan; Department of Audiology and Speech Language Pathology and School of Medicine, Mackay Medical College, #46, Sec. 3, Zhongzheng Rd., Sanzhi Dist., New Taipei City 252, Taiwan.
authors: Kuo-Sheng
authors: KS
authors: Lee
authors: Institute of Public Health and Community Medicine Research Center, National Yang-Ming University, #155, Sec. 2, Linoon Street, Pei-Tou Dist., Taipei 112, Taiwan.
authors: Pesus
authors: P
authors: Chou
mesh_terms: D000293:Adolescent; D000328:Adult; D001424:Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D009333:Neck / Q000382:microbiology*; D011183:Postoperative Complications; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D014068:Tonsillectomy / Q000009:adverse effects*; D014069:Tonsillitis / Q000453:epidemiology / Q000601:surgery*; D055815:Young Adult