title: The investigation of the recurrence rate of cholesteatoma using Kaplan-Meier survival analysis.
abstract: OBJECTIVE
  To investigate the recurrence rate of cholesteatoma using Kaplan-Meier survival analysis.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Three hundred forty-five patients with middle ear cholesteatoma operated on by the same surgeon between 1987 and 2002.
  
  
  METHODS
  The cumulative recurrence rate of cholesteatoma during a 5-year follow-up period was calculated using Kaplan-Meier survival analysis.
  
  
  RESULTS
  The overall 5-year recurrence rate was 11.8%. The recurrence rate increased with the follow-up time. The 5-year recurrence rate was 3.9% in patients treated with canal wall down tympanoplasty (CWDT) and 16.7% in patients treated with intact canal wall tympanoplasty (ICWT) or canal wall reconstruction (CWR) after CWDT with a significant difference (p < 0.01). The 5-year recurrence rate was 26.0% in patients operated on between 1987 and 1996 and 0.7% in patients operated on between 1997 and 2002, again with a significant difference (p < 0.001).
  
  
  CONCLUSIONS
  Kaplan-Meier survival analysis should be used for calculating the recurrence rate of cholesteatoma. Although this analytic method further demonstrates that CWDT is a more reliable surgical method than ICWT/CWR in reducing cholesteatoma recurrence, clinical judgment should be exercised, and we continue to recommend that a flexible approach should be adopted in deciding whether to perform CWDT or ICWT/CWR for individual cases.
authors.affiliation: Department of Otolaryngology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan. ymishiro@hyo-med.ac.jp
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Mishiro
authors.forename: Masafumi
authors.initials: M
authors.lastname: Sakagami
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kitahara
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Kondoh
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Okumura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D018424:Cholesteatoma, Middle Ear / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D013997:Time Factors; D014433:Tympanoplasty; D055815:Young Adult