Sensitivity and specificity of asthma definitions and symptoms used in a survey of childhood asthma.

We compared the ability of definitions/symptoms of asthma to identify urban, elementary schoolchildren with physician-diagnosed asthma and bronchial hyperresponsiveness (BHR) post-exercise challenge. Definitions of asthma from the literature were compared, including American Thoracic Society (ATS) and British Medical Research Council (BMRC) definitions. Modified ATS had the highest sensitivity (77%), whereas BMRC had the highest specificity (99%). The most sensitive symptom was "wheeze with cold" (89%). The most specific symptoms were "medication required," and "breathing normal between attacks" (95%). Definitions and symptoms were poor predictors of BHR. Researchers can use these estimates in selecting and defining specific populations of children with asthma.