Sensitivity and specificity of the histamine challenge test for the diagnosis of asthma in an unselected sample of children and adolescents

Abstract

The purpose of this investigation was to study factors of importance for the degree of bronchial responsiveness and, furthermore, to evaluate the sensitivity, specificity and predictive value of a bronchial challenge test with histamine for the diagnosis of asthma in 495 randomly selected children and adolescents, aged 7-16 yrs, from Copenhagen, Rigshospitalet. Detailed history about allergic symptoms, physical examination and bronchial histamine challenge tests were performed at the out-patient clinic. Asthma, atopic disease and height were found to be of great importance for the degree of bronchial responsiveness, whereas the age, sex and smoking habits were of no significance. The percentage of asthmatics with bronchial hyperresponsiveness, i.e. sensitivity to the test, increased towards 100% on inhaling increasing concentrations of histamine, but this was accompanied by a decrease in specificity and predictive values of positive test in regard to the diagnosis of asthma. However, lower concentrations of histamine may be preferable in order to distinguish between asthma and non-asthma in population samples, as inhalation of 2.4 mg.ml-1 and provocative concentration producing a 20% fall in forced expiratory volume in one second (FEV1) (PC20) provided an acceptable sensitivity (57%), specificity (98%), and predictive value of a positive test (60%). We conclude that as regards the diagnosis of asthma, a low predictive value confirms that the bronchial challenge test plays only a supplementary, but valuable, role in detecting the disease in population samples.

Nonspecific challenge test for the diagnosis of asthma in a general population sample

“…We have read the recent paper by BAcKER and coworkers [1] in which they confirm findings of previous surveys that there is a considerable overlap in bronchial responsiveness between asthmatics and non-asthmatics. Most of these surveys have used a fixed threshold level as a positive test criterion, for instance PC 20 FEV 1 $8 g•l methacholine.…”

Use of peak flow variability and methacholine responsiveness in predicting changes from pre-test diagnosis of asthma

“…However, these objective measures do not always correlate strongly with each other [6] and may-measure different pathophysiological aspects of the disease [7±9]. In epidemiological studies, both AHR and PEF variability have low sensitivities and positive predictive values [10,11], but relatively high negative predictive values for the diagnosis of asthma [10]. In clinical practice, both tests are used routinely and widely in the diagnosis and assessment of asthma [12,13].…”