Novel measure of lung function for assessing disease activity in asthma

INTRODUCTION: In asthma, lung function measures are often discordant with clinical features such as disease activity or control. METHODS: We investigated a novel technique that provides a measure (σCL) of unevenness (inhomogeneity) in lung inflation/deflation. In particular, we compared σCL with FEV(1)% predicted (FEV(1)%pred) as measures of disease activity in the asthmatic lung. RESULTS: σCL correlated modestly with FEV(1)%pred. However, σCL is not simply a proxy for FEV(1)%pred as the effects of salbutamol on the two parameters were unrelated. Importantly, σCL reflected disease control better than FEV(1). DISCUSSION: We conclude that σCL shows promise as an objective measure of disease activity in asthma.