title: Cholesteatoma in Danish children - a national study of changes in the incidence rate over 34 years.
abstract: OBJECTIVE
  To describe temporal trends in the incidence rate of surgically treated middle ear cholesteatoma in Danish children from 1977 to 2010.
  
  
  METHODS
  Data on surgically treated middle ear cholesteatoma was drawn from the Danish National Patient Register. A change in incidence rate over time was examined using Poisson regression analysis, while the cumulative incidence proportion was estimated using life-tables.
  
  
  RESULTS
  A total of 5850 cases of surgically treated middle ear cholesteatoma distributed among 3874 children aged 0-15 years were identified. From 1977 to 2002 the age-standardized incidence rates for first-time surgically treated middle ear cholesteatoma increased from 8 to 15 per 100,000 person-years with an estimated annual increase of 1.8% (95% confidence interval (CI) 1.3-2.2%). From 2002 to 2010 the rates decreased from 15 to 10 per 100,000 person-years with an annual decrease of 5.4% (95% CI 3.2-7.5%). Age-specific incidence rates were at maximum around the age of 9 years during the whole period. The estimated cumulative incidence proportion at age 16 years based on the 2010 age-specific incidence rates was 0.16% (95% CI 0.09-0.32%) compared with 0.20% (95% CI 0.11-0.37%) based on the 2000 age-specific incidence rates.
  
  
  CONCLUSIONS
  From 2002 to 2010 there was a decrease in the incidence rate of first-time surgically treated middle ear cholesteatoma. The decrease was preceded by a significant increase in the incidence rate of middle ear ventilation tube insertion. However, further studies are needed to find possible explanations for the decrease.
authors.affiliation: Department of ENT Head & Neck Surgery, Odense University Hospital, Odense, Denmark. Electronic address: bjarkid@dadlnet.dk.
authors.forename: Bjarki Ditlev
authors.initials: BD
authors.lastname: Djurhuus
authors.affiliation: Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark.
authors.forename: Axel
authors.initials: A
authors.lastname: Skytthe
authors.affiliation: Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark.
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
authors.affiliation: Department of ENT Head & Neck Surgery, Odense University Hospital, Odense, Denmark.
authors.forename: Christian Emil
authors.initials: CE
authors.lastname: Faber
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D002781:Cholesteatoma / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D018424:Cholesteatoma, Middle Ear / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008876:Middle Ear Ventilation / Q000706:statistics & numerical data; D013997:Time Factors
keywords: Children; Cholesteatoma; Denmark; Epidemiology; Incidence rates