[Is non-allergenic bronchial hyperreactivity a good diagnostic test for asthma?]

The measurement of non-allergic bronchial hyperreactivity brings limited information in the diagnosis of asthma, whether for epidemiological purposes or for an individual patient. Its sensitivity and specificity in the general population amount to 46 and 89% respectively. It follows that the positive and negative predictive values are of little use when the prevalence of asthma lies between 1 and 10%. The situation is different, more complex, but not necessarily more favorable when one deals with one given patient. The characteristics of the test may vary as a function of the severity of the disease (concept of spectrum bias). Furthermore, the differential diagnosis will be made for other diseases that can also be associated with bronchial hyperreactivity. The negative and positive predictive values of this test will therefore be sufficiently informative only when the diagnosis is already certain.