Comparison of the FEV1 value from five reference equations: ESCS 71|83|93, NHANES and GLI

Abstract

Introduction: Spirometry plays a fundamental role in the evaluation of pulmonary function. In 2012, with the publication of the Global Lungs Initiative (GLI) reference equations, the discussion of the equations chosen by each laboratory was once again in the spotlight. Aim: The aim was to compare the FEV1 value from different reference equations available, namely the European Community for Steel and Coal (ECSC) 71|83|93, the National Health and Nutrition Examination Survey (NHANES) III and GLI. Methods: We retrospectively selected spirometries from 30 individuals (63% men), aged between 51 and 82 years, who met the criteria of acceptability and reproducibility. We calculated the percentage of the predicted forced expiratory volume in 1 second (FEV1) using all the mentioned equations. In order to standardize the sample, only patients with bronchial obstruction were chosen (FEV1/FVC ratio Results: Only the results for GLI and ECSC 71 are not significantly different (pairwise t-tests, p Discussion: As the equations produce significantly different values for predicted FEV1, the resulting classification of the obstruction will also be different. Therefore, it is critical that all reports clearly state the equation used, until laboratories agree on the standard equation to use.