Do changes in spirometric indices and FeNO predict asthma outcomes in children? An individual patient data analysis using results from seven FeNO trials

Introduction: Guidelines recommend spirometry and/or fractional exhaled nitric oxide (FeNO) as objective measurements to guide asthma management. Our hypothesis was that falling FEV1, FEV1/FVC ratio or FEF25-75 or rising FeNO measurements are associated with future adverse asthma outcomes. Methods: Data were obtained from 7 trials using FeNO to guide asthma treatment. Predictors were change in % FEV1, FEV1/FVC ratio or FEF25-75 and...