Uncertain role of spirometry in managing childhood asthma in the UK 2019

Asthma guidelines recommend that spirometry should be used for monitoring the condition in children. Surprisingly there is no link between rising or falling spirometry and treatment change. One guideline recommends that treatment might be increased if the per cent forced expiratory volume in 1 s (FEV1) is <80% or <60% of predicted.1 However, lung function is usually within the normal range in children2 with asthma, so these cut-offs are not helpful. Recently published data3 provide evidence of proof-of-concept and inform sample size calculation for a ‘spirometry trial’.