Ecuaciones de referencia para informe de espirometrías. ¿Será tiempo de adoptar las ecuaciones de la Global Initiative for Lung Function?

ATS/ERS recommend the use of national reference values for the interpretation of spirometry. Reference values were published (2014) in general adult Chilean population, which are different from those of Knudson currently in use. However, most pulmonary function laboratories continue to use these latter equations. Multi-ethnic Global Lung Function Initiative (GLI) equations were published (2012) in order to standardize the interpretation of pulmonary function tests worldwide. Our objective was to evaluate the agreement in the spirometric reports between the most used equations in Chile with those from GLI. Methods: We compared the agreement in the interpretation of the spirometric pattern (normal, obstructive and restrictive) and the degree of alteration between GLI with Gutierrez 2014, with Knudson and with NHANES III according to recommendations of the Chilean Society of Respiratory Diseases, through the Kappa concordance coefficient (K). The sample correspond to 315 adults over 40 years of age (55% women, 59.3 ± 9.2 years-old), smokers or ex-smokers, healthy or with COPD, who underwent spirometry with a bronchodilator as part of a respiratory check-up. Differences were plotted using the Bland-Altman method. Results: agreement for pattern between GLI with Gutierrez 2014, with Knudson and with NHANES III was good (K = 0.73, 0.71 and 0.77 respectively) and also was good for the pattern and degree of alteration (K = 0.68, 0.67 and 0.76 respectively). Conclusions: We found a good agreement between the equations most used in Chile and those from the GLI, for a sample that includes subjects with and without lung disease, smokers and ex-smokers.