title: Verifying a questionnaire diagnosis of asthma in children using health claims data.
abstract: BACKGROUND
  Childhood asthma prevalence is widely measured by parental proxy report of physician-diagnosed asthma in questionnaires. Our objective was to validate this measure in a North American population.
  
  
  METHODS
  The 2884 study participants were a subsample of 5619 school children aged 5 to 9 years from 231 schools participating in the Toronto Child Health Evaluation Questionnaire study in 2006. We compared agreement between "questionnaire diagnosis" and a previously validated "health claims data diagnosis". Sensitivity, specificity and kappa were calculated for the questionnaire diagnosis using the health claims diagnosis as the reference standard.
  
  
  RESULTS
  Prevalence of asthma was 15.7% by questionnaire and 21.4% by health claims data. Questionnaire diagnosis was insensitive (59.0%) but specific (95.9%) for asthma. When children with asthma-related symptoms were excluded, the sensitivity increased (83.6%), and specificity remained high (93.6%).
  
  
  CONCLUSIONS
  Our results show that parental report of asthma by questionnaire has low sensitivity but high specificity as an asthma prevalence measure. In addition, children with "asthma-related symptoms" may represent a large fraction of under-diagnosed asthma and they should be excluded from the inception cohort for risk factor studies.
authors: Division of Respiratory Medicine, Hospital for Sick Children, Toronto, Canada.
authors: Connie L
authors: CL
authors: Yang
authors: Teresa
authors: T
authors: To
authors: Richard G
authors: RG
authors: Foty
authors: David M
authors: DM
authors: Stieb
authors: Sharon D
authors: SD
authors: Dell
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007344:Insurance Claim Reporting; D008297:Male; D009864:Ontario / Q000453:epidemiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D014505:Urban Population