In search of childhood asthma: questionnaire, tests of bronchial hyperresponsiveness, and clinical evaluation

Abstract

Background:The definition or diagnosis of asthma is a challenge for both clinicians and epidemiologists. Symptom history is usually supplemented with tests of bronchial hyperresponsiveness (BHR) in spite of their uncertainty in improving diagnostic accuracy. Methods: To assess the interrelationship between respiratory symptoms, BHR, and clinical diagnosis of asthma, the respiratory symptoms of 1633 schoolchildren were screened using a questionnaire (response rate 81.2%) and a clinical study was conducted in a subsample of 247 children. Data from a free running test and a methacholine inhalation challenge test were available in 218 children. The diagnosis of asthma was confirmed by a paediatric allergist. Results: Despite their high specificity (>0.97), BHR tests did not significantly improve the diagnostic accuracy after the symptom history: area under the receiver operator characteristic (ROC) curve was 0.90 for a logistic regression model with four symptoms and 0.94 for the symptoms with free running test and methacholine inhalation challenge results. On the other hand, BHR tests had low sensitivity (0.35-0.47), whereas several symptoms had both high specificity (>0.97) and sensitivity (>0.7) in relation to clinical asthma, which makes them a better tool for asthma epidemiology than BHR. Conclusions: Symptom history still forms the basis for defining asthma in both clinical and epidemiological settings. BHR tests only marginally increased the diagnostic accuracy after symptom history had been taken into account. The diagnosis of childhood asthma should not therefore be overlooked in symptomatic cases with no objective evidence of BHR. Moreover, BHR should not be required for defining asthma in epidemiological studies.

Childhood eczema and asthma incidence and persistence: A cohort study from childhood to middle age

“…Childhood asthma defined by the parent would have included nonasthmatic wheeze. We and others have found that parent-defined childhood asthma compares well with the definition including bronchial hyperresponsiveness, 42,43 and a looser definition would shift estimates toward the null. 44 The use of ''doctor-diagnosed asthma'' may result in underdiagnosis.…”

Health consequences associated with frequent wheezing in adolescents without asthma diagnosis

“…These studies determined that the video questionnaire was a reliable method for determining asthma prevalence [14-16, 24, 25, 31]. Recent research has shown that bronchial hyperresponsiveness (BHR) tests had a low sensitivity (0.35-0.47), whereas using asthma symptoms had high specificity (w0.97) and sensitivity (w0.7) in relation to clinical asthma, which makes them a better tool for asthma epidemiology than BHR [30,[32][33][34].…”

Childhood allergic rhinitis predicts asthma incidence and persistence to middle age: A longitudinal study

“…Despite this limitation, we believe that parent-defined childhood asthma is acceptable. Others have found that this definition compares well with one including bronchial hyperresponsiveness, 38,39 and a looser definition will shift estimates toward the null. 40 The use of physician-diagnosed asthma can result in underdiagnosis.…”