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|Title: ||The Accuracy of Epidemiologic Definitions of Childhood Asthma Using a Clinical Reference Standard|
|Authors: ||Yang, Connie|
|Advisor: ||Dell, Sharon|
|Department: ||Medical Science|
|Issue Date: ||24-Jul-2012|
|Abstract: ||This study determined the sensitivity and specificity of questionnaires and administrative databases compared to a clinical reference standard for asthma.
208 schoolchildren from a population-based sample participated. They underwent a physician assessment, spirometry, methacholine challenge, exhaled nitric oxide and skin testing. Data was linked to the Ontario Asthma Surveillance Information System.
“Questionnaire diagnosis” was an affirmative response to physician-diagnosed asthma. “Database diagnosis” was 2 outpatient visits or 1 hospitalization within 2 years. “Clinical diagnosis” required a physician assessment and objective findings of asthma.
“Questionnaire diagnosis” of asthma was specific (92.1%) but not sensitive (75.3%) compared to the “clinical diagnosis”. “Database diagnosis” was sensitive (87.5%) but not specific (64.8%). Both sources had an excellent negative predictive value (97-98%) but poor positive predictive value (24-55%).
Epidemiologic methods accurately identify those without asthma but are poor at identifying those with asthma, leading to an overestimation of asthma prevalence and dilution of risk estimates.|
|Appears in Collections:||Master|
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