The airway hyperresponsiveness prediction value of digitalized lung sound collected during forced expiration in bronchial provocation test

BACKGROUND: This study investigated the acoustic characteristics of forced expiratory lung sounds during bronchial provocation tests and their predictive value for airway hyperresponsiveness (AHR). RESEARCH DESIGN AND METHODS: Participants underwent a bronchial provocation test with incremental methacholine doses (0.072-1.25 mg). Forced expiratory volume in the first second (FEV1) was measured using spirometry, with pre-saline FEV1 as the baseline. AHR was defined as a ≥ 20% decline in FEV1%Ref (FEV1 relative to baseline). Simultaneously, lung sounds were recorded from the right lower lung field. Thirty-five acoustic features were extracted from the first-second forced expiratory lung sound, including 24 spectral parameters, 5 mel-frequency cepstral coefficients (MFCCs), and 6 entropy parameters. Correlation analysis, group comparisons, and logistic regression were conducted to assess the relationship between acoustic features and AHR. Logistic regression identified effective power (PT) and MFCC5 as independent predictors, yielding an AUC of 0.856 (95% CI: 0.769-0.944). CONCLUSIONS: Acoustic features of breath sounds can predict AHR, offering a potential noninvasive alternative to bronchial challenge tests.