LAUSR

The Lancet Asthma Commission calls for objective measurements to support asthma diagnosis, especially for children [1]. The expiratory variability index (EVI) is a novel method of testing lung function that can be measured passively at night with an impedance pneumography (IP) technique using four skin electrodes and a small body-worn recorder. The aim of EVI is to measure variation in flow–volume curve shapes within 15–45% of the expired volume. It has been demonstrated that normal variations in the curve shapes are mainly caused by comparing different sleep cycles [2], which are reduced in the presence of bronchial obstructions [3]. Inhaled corticosteroid treatment improves expiratory variability index in steroid-naïve asthmatic children aged 4–7 years https://bit.ly/3n4vBT3