Forced oscillatory parameters as predictors of COPD assessment test improvement in untreated COPD patients

• Published in: Respiratory Physiology & Neurobiology Vol. 296; p. 103809
• Main Authors: Takahashi, Shingo, Shirai, Toshihiro, Hirai, Keita, Akamatsu, Taisuke
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2022; Elsevier BV
• Subjects: Adult; Aged; COPD assessment test; Female; Forced Expiratory Volume; Forced Expiratory Volume - physiology; Forced oscillation technique; Humans; Male; Middle Aged; Minimal clinically important difference; Oscillometry; Oscillometry - standards; Outcome Assessment, Health Care; Outcome Assessment, Health Care - standards; Pulmonary Disease, Chronic Obstructive; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - therapy; Recursive partitioning analysis; Respiratory Function Tests; Respiratory Function Tests - standards; Sensitivity and Specificity; Severity of Illness Index; Spirometry; Spirometry - standards; GOLD; mMRC; R50 and R20; Forced oscillation technique; EFL; FOT; LAMA; FVC; Rrs; Recursive partitioning analysis; COPD assessment test; MCID; CAT; LABA; Xrs; FEV1; ΔX5; X5; Minimal clinically important difference; COPD
• ISSN: 1569-9048; 1878-1519; 1878-1519
• DOI: 10.1016/j.resp.2021.103809

Few studies have examined whether baseline spirometry and the forced oscillation technique (FOT) would predict The COPD Assessment Test (CAT) score improvement after treatment of untreated COPD patients. The study subjects included 65 untreated COPD patients. They underwent the CAT, spirometry, and FOT (MostGraph) before and after treatment for more than 2 months. In addition, recursive partitioning analysis was performed using spirometry and the FOT parameters to identify the predictors of CAT improvement (CAT score ≥2). CAT scores and lung function significantly improved after treatment. Recursive partitioning analysis identified 3 improved classes, defined by Rrs at 20 Hz (R20), Xrs at 5 Hz (X5), and ΔX5, but not by spirometry. The accuracy of predicting CAT improvement was as follows: odds ratio, 25.3; 95 % confidence interval, 6.1 to 104.1; sensitivity, 91.2 %; specificity, 71.0 %; positive likelihood ratio, 3.14; and negative likelihood ratio, 0.12. FOT helps predict improved health status in untreated COPD patients.