Small airway abnormalities as a marker of early lung injury: challenges ahead

Abstract

In The Lancet Global Health, Ben Knox-Brown and colleagues1 reported the prevalence and risk factors of small airways obstruction across several world regions using data from Burden of Obstructive Lung Disease (BOLD) study. Small airways obstruction was defined as either mean forced expiratory flow rate between 25% and 75% of the forced vital capacity (FEF25–75) less than the lower limit of normal (LLN) or forced expiratory volume in 3 s to forced vital capacity ratio (FEV3/FVC ratio) less than the LLN.