Comparison of New Spirometry Measures to Diagnose COPD

• Published in: Respiratory care 2023-03, Vol.68 (3), p.366-373
• Main Authors: Giraldo, Angélica M Moreno, Cadavid, Luis F Giraldo, Rosas, Daniel Botero, Quintero, Eduardo Tuta, Maldonado-Franco, Adriana, Murcia, Hermencia C Aponte, Suárez, Carlos E Avellaneda, Cely, Lina María Morales, Bastidas, Alirio Rodrigo
• Format: Article
• Language: English
• Subjects: Aged; Care and treatment; Cross-Sectional Studies; Diagnosis; Evaluation; Female; Forced Expiratory Volume; Humans; Lung diseases, Obstructive; Male; Original Research; Pulmonary Disease, Chronic Obstructive - diagnosis; Reproducibility of Results; Spirometry; Vital Capacity
• ISSN: 0020-1324; 1943-3654
• DOI: 10.4187/respcare.10191

COPD is diagnosed by using FEV /FVC, which has limitations as a diagnostic test. We assessed the validity of several measures derived from the expiratory phase of the flow-volume curve obtained from spirometry to diagnose COPD: the slopes that correspond to the volume expired after the 50% and 75% of the FVC, the slope formed between the peak expiratory flow (PEF) and the FVC, and the area under the expiratory flow/volume curve. We conducted a cross-sectional diagnostic test study in 765 consecutive subjects referred for spirometry because of respiratory symptoms. We compared the reproducibility and accuracy of the proposed measures against post-bronchodilator FEV /FVC < 0.70. We also evaluated the proportion of respiratory symptoms for the FEV /FVC, FEV per FEV in the first 6 s (FEV ), and the PEF slope. The subjects had a mean age of 65.8 y, 57% were women, and 35% had COPD. The test-retest intraclass correlation coefficient values were 0.89, 0.85, and 0.83 for FEV /FVC, FEV /FEV , and the PEF slope, respectively. The area under the curve values were 0.93 (expiratory flow/volume), 0.96 (potential expiratory flow/volume), 0.97 (potential expiratory flow/volume at 75% of FVC), and 0.82 (potential expiratory flow/volume at 50% of FVC). The area under the receiver operating characteristic curve was 0.99 for FEV /FEV , 0.99 for the slope at 50% of the FVC, and 0.98 for the PEF slope. The FEV /FEV , PEF slope, and 50% FVC slopes had similar diagnostic performances compared with FEV /FVC.