Prevalence (%) of post-BD airway obstruction and indices of spirometry quality by study site.

FET = Forced expiratory time; Grade A = fulfilling quality criteria by American Thoracic Society/European Respiratory Society (ATS-ERS 2005), three acceptable maneuvers with Forced expiratory volume in one second (FEV)1 and Forced vital capacity (FVC) reproducible to 150 mL; Grade A,B,C = Adequate quality tests by (ATS-ERS 2005): two or three acceptable maneuvers with FEV1 and FVC reproducible to 250 mL. COV = within-test coefficient of variability. LLN = Lower limit of normal according to PLATINO without bronchodilator reference values. See Text S1 for pre-BD results.