The relation between cough sound characteristics and lung function

Rationale: Amongst Dutch children, 7-10% suffers from asthma. To obtain an objective measurement of asthma, this study explores the feasibility of measuring coughs as an indication of the Forced Expiratory Volume in 1 second (FEV1). Objective: To investigate the relation between cough sound characteristics and the Exercise Challenge Test (ECT) induced changes in the FEV1. Method: Patients who were scheduled for an ECT were recruited to take part in this study. Coughs were measured with an accelerometer and smart phone. Lung function was measured with spirometry. Several parameters were derived, such as the dominant frequency, in all phases of the cough. Results: Sixteen children were included, of who 5 experienced a decrease in FEV1 during the ECT >10%. A broader interquartile range was found of the higher dominant frequency in the second phase of the cough, measured after exercise. This dominant frequency was significantly higher in comparison to the baseline measurement (p <0.05). Discussion: Measuring more patients could reveal trends in asthmatic patients' coughs. Future work should focus on if cough parameters are an indication of a decrease in FEV1. Conclusion: In this study, no relation between cough sound parameters and FEV1 was found.