title: The reliability of self-reported childhood otitis media by adults.
abstract: OBJECTIVE
  To estimate reliability of retrospective questionnaire data on childhood recurrent otitis media, and to identify factors influencing inconsistency in self-report.
  
  
  METHODS
  Retrospective questionnaire data from a population-based sample of 4430 Norwegian twins who participated in two questionnaire surveys, 6 years apart, containing identical questions on otitis media. Main outcome measure was individual consistency in reporting of otitis media. The tetrachoric correlation and Cohen's Kappa were used to measure reliability. Inconsistent and consistent responders were compared on medical history and mental distress. The use of twin data made it possible to test whether inconsistent responders represent a group with intermediate levels of otitis media severity.
  
  
  RESULTS
  The test-retest tetrachoric correlation was 0.82 and Kappa was 0.53. Inconsistency in response was not associated with mental distress, but related to reported number of otitis media episodes per year, use of medical services and history of ear surgery.
  
  
  CONCLUSIONS
  Retrospective self-reported otitis media is a relatively reliable measure. The study suggests that reporting inconsistency is likely to be associated with less severe disease. The finding that reporting pattern is related to disease severity is in accordance with the proposed need for a uniform agreement on the definition of the term "recurrent otitis media" for research purposes.
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, Pb 4404 Nydalen, N-0403 Oslo, Norway. ellen.kvestad@fhi.no
authors.forename: Ellen
authors.initials: E
authors.lastname: Kvestad
authors.forename: Kari Jorunn
authors.initials: KJ
authors.lastname: Kvaerner
authors.forename: Espen
authors.initials: E
authors.lastname: Røysamb
authors.forename: Kristian
authors.initials: K
authors.lastname: Tambs
authors.forename: Jennifer Ruth
authors.initials: JR
authors.lastname: Harris
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
mesh_terms: D000328:Adult; D002648:Child; D003625:Data Collection / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D010033:Otitis Media / Q000175:diagnosis*; D015203:Reproducibility of Results; D012650:Self Disclosure; D011795:Surveys and Questionnaires