TY - JOUR T1 - Comparison of New Spirometry Measures to Diagnose COPD JF - Respiratory Care DO - 10.4187/respcare.10191 SP - respcare.10191 AU - Angélica M Moreno Moreno Giraldo AU - Luis F Giraldo Cadavid AU - Daniel Botero Rosas AU - Eduardo Tuta Quintero AU - Adriana Maldonado-Franco AU - Hermencia C Aponte Murcia AU - Carlos E Avellaneda Suárez AU - Lina María Morales Cely AU - Alirio Rodrigo Bastidas Y1 - 2022/11/22 UR - http://rc.rcjournal.com/content/early/2022/11/22/respcare.10191.abstract N2 - BACKGROUND: COPD is diagnosed by using FEV1/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.METHODS: 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 FEV1/FVC < 0.70. We also evaluated the proportion of respiratory symptoms for the FEV1/FVC, FEV1 per FEV in the first 6 s (FEV6), and the PEF slope.RESULTS: 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 FEV1/FVC, FEV1/FEV6, 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 FEV1/FEV6, 0.99 for the slope at 50% of the FVC, and 0.98 for the PEF slope.CONCLUSIONS: The FEV1/FEV6, PEF slope, and 50% FVC slopes had similar diagnostic performances compared with FEV1/FVC. ER -