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.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OTU.1807/32502 |
| Date | 24 July 2012 |
| Creators | Yang, Connie |
| Contributors | Dell, Sharon |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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