Vilozni D, et al. - A cross-sectional study was conducted to ascertain whether measuring inspiratory capacity (IC) during spirometry, may add clinical value to FEV₁ measurements in cystic fibrosis (CF) subjects. For this investigation, researchers retrospectively collected anthropometric, clinical, spirometry, and static lung volume data from 98 of 165 subjects with CF registered in The Edmond and Lily Safra Children's Hospital, Sheba Medical Centre, Israel. The findings suggested that measuring IC in CF subjects might reveal silent worsening of lung function as showed by a decline in IC < 50% predicted while FEV₁ is still > 40% predicted and this condition may lead to inefficient breathing at high lung volumes, which might explain a subjective sensation of breathlessness and lead to an increase in hospitalization days/year.