[The diagnosis of COPD is recommendation dependent].

Background: Different spirometric criteria are recommended to diagnosis chronic obstructive pulmonary disease (COPD): -American Thoracic Society/European Respiratory Society (ATS/ERS), Global initiative for chronic Obstructive Lung Disease (GOLD): a post bronchodilator (PBD) ratio between the 1st second Forced Expiratory Volume and Forced Vital Capacity (FEV1/FVC) < 0.70; -Thoracic Society of Australia and New Zealand (ANZTS): a PBD FEV1/FVC < 0.70 and a PBD FEV1 < 80%; -British Thoracic Society (BTS): a before BD (BBD) FEV1/FVC < 0.