ECSC vs. GLI: Which of these spirometric references equations will be more appropriate for a local portuguese adult population?

Abstract

Introduction: American and European societies recommend laboratories to select the most appropriate reference equations for their population. Aim: To evaluate which of two reference equations ECSC and GLI is the most appropriate for the population of Vila Franca de Xira (VFX). Methods: This study included 64 healthy non-smoking caucasian volunteers, aged 26-80 years. A predefined questionnaire for screening of diseases and symptoms was used and the spirometry was performed according to ATS/ERS2005. The selected reference equations were compared with measurements obtained from this sample. The reference equation that provided the sum of residuals (observed – predicted for each subject) closest to zero was considered the most appropriate. A significance level of 5% was considered. Results: The mean values calculated using the ECSC equations were closest to the mean values of FVC (4.55 L) and FEV1 (3.07 L) obtained for men, +0.124 (pm=0.351) and +0.082 (pm=0.405), respectively. In women, the mean values predicted by the GLI equations were closest to the mean values of FVC (3.29 L) and FEV1 (2.76 L), -0.101(pw=0.229) and -0.006 (pw=0.322), respectively. A significant difference was found only for ECSC equation in women regarding FVC and FEV1 mean values, -0.336 (pw Conclusions: Problably, GLI is the most appropriate reference equation for this population. Spirometric values in a healthy local population are crucial to correctly choose which reference equation should be used.