Cut-off value for exercise-induced bronchoconstriction based on the features of the airway obstruction

Abstract

The current cut-off value for diagnosing exercise-induced bronchoconstriction (EIB) in adults—percent fall in FEV1 (ΔFEV1) ≥ 10% after exercise challenge test (ECT)—has low specificity and weak evidences. Therefore, this study aimed to identify the cut-off value for EIB that provides the highest diagnostic sensitivity and specificity. Participants who underwent the ECT between 2007 and 2018 were categorized according to ΔFEV1: definite EIB (ΔFEV1 ≥ 15%), borderline (10% ≤ ΔFEV1 < 15%), and normal (ΔFEV1 < 10%). Distinct characteristics of the definite EIB group were identified and explored in the borderline EIB group. A receiver operating characteristic curve was plotted to determine the optimal cut-off value. Of 128 patients, 60 were grouped as the definite EIB group, 23 as the borderline group, and 45 as the normal group. All participants were men, with a median age of 20 years (interquartile range [IQR:] 19–23 years). The definite EIB group exhibited wheezing on auscultation (P < 0.001), ΔFEV1/FVC ≥ 10% (P < 0.001), and ΔFEF25–75% ≥ 25% (P < 0.001) compared to other groups. Eight (8/23, 34.8%) patients in the borderline group had at least one of these features, but the trend was more similar to that of the normal group than the definite EIB group. A cut-off value of ΔFEV1 ≥ 13.5% had a sensitivity of 98.5% and specificity of 93.5% for EIB. Wheezing on auscultation, ΔFEV1/FVC ≥ 10%, and ΔFEF25–75% ≥ 25% after ECT may be useful for the diagnosis of EIB, particularly in individuals with a ΔFEV1 of 10–15%. For EIB, a higher cut-off value, possibly ΔFEV1 ≥ 13.5%, should be considered as the diagnostic criterion.

Novel Artificial Intelligence-Based Technology to Diagnose Asthma Using Methacholine Challenge Tests

“…This value is considered a more sensitive indicator of airway reversibility and treatment responsiveness than the FEV 1 value in patients with asthma. 34 35 36 37 38 The significance of the FEF 25%–75% value in clinical decision-making beyond the FEV 1 value is controversial. 39 However, in another study that examined factors to detect asthma and chronic obstructive pulmonary disease using ML techniques, the most prominent attribute for asthma diagnosis was the FEF 25%–75% value, consistent with the results of our study.…”