%0 Journal Article
%T Verifying a questionnaire diagnosis of asthma in children using health claims data
%A Connie L Yang
%A Teresa To
%A Richard G Foty
%A David M Stieb
%A Sharon D Dell
%J BMC Pulmonary Medicine
%D 2011
%I BioMed Central
%R 10.1186/1471-2466-11-52
%X 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.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%).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.Parental proxy report of physician-diagnosed asthma (questionnaire diagnosis) is the standard measure of childhood asthma prevalence used in national health surveys and epidemiological studies. The International Study of Allergies and Asthma in Childhood (ISAAC) questionnaire is the current gold standard for ascertaining asthma outcomes in epidemiologic studies [1]. The "ever wheeze" question is often used to compare asthma prevalence between countries. For international studies, a symptom-based definition is less subject to bias than a diagnosis-based definition[2]. However, for national studies that evaluate risk factors, a more specific definition is often desired [3-5]. In these studies, lifetime asthma is measured by affirmative response to the question: "Has your child ever had asthma?" and is further defined to be "Doctor diagnosed asthma" if there is an affirmative response to the question "Has this been diagnosed
%U http://www.biomedcentral.com/1471-2466/11/52