Background: Recently, the severities of chronic obstructive pulmonary disease (COPD) can also be assessed by impulse oscillometry (IOS). This study aimed to explore a new classification of severity of COPD based on IOS and associations with acute exacerbations (AE) in patients with COPD.
Methods: The data of our study were based on the baseline and 2-year follow-up data of a prospective cohort in China. COPD was defined as post-bronchodilator FEV1/FVC <0.70. A new severity classification (staging of airflow obstruction by IOS, SAIO) was evaluated based on IOS parameters (R5, R5-R20, and X5 z-scores). We quantified using the weighted Bangdiwala B for agreement of severities of COPD between IOS parameters and FEV1%pred. The differences among SAIO stages were performed in symptom scores and imaging using analysis of covariance, and in the AE using Poisson regression.
Results: Overall, 833 patients with COPD were included in this study. The weighted Bangdiwala B of R5, R5-R20, X5 z-scores, and FEV1%pred for evaluating agreement of the severities of COPD was 0.68, 0.70 and 0.83, respectively. The SAIO classifications system identified a greater number of patients with stage III-IV. SAIO provided significant discrimination between the stage I and stage III, IV for symptom scores, emphysema, and air trapping. SAIO provided significant discrimination between the stage I and other stages for AE.
Conclusions: The SAIO classifications provide discrimination between the stage I and stage III, IV for symptom scores, emphysema, air trapping, and AE, similar to the GOLD classifications.
Trial registration: Chinese Clinical Trial Registry, ChiCTR1900024643. Registered on 19 July, 2019.
Keywords: Acute exacerbations; Impulse oscillometry; Lung function decline; Severity of chronic obstructive pulmonary disease.
Copyright © 2024. Published by Elsevier España, S.L.U.