Spirometry measurements
Spirometry measurements were conducted using a Vyntus® APS/IOS (Vyaire
GmbH, Höchberg, Germany), calibrated daily with a 3 L syringe according
to the manufacturer’s instructions, and analysed using the
SentrySuite® software package (version 3.10). Spirometry was performed
in accordance with ATS/ERS guidelines and after explanation and
demonstration of the correct execution technique [57]. Among
measurements fulfilling acceptability and usability criteria, three
acceptable flow volume loops (FVL) were selected, with the second highest
forced vital capacity (FVC) and forced expiratory volume in 1 second
(FEV1) within 0.1 L or 10% of the highest value.