External validation of an IOS-derived model for airflow obstruction and COPD in a community-based cohort

/FVC < 0.70 as COPD. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of the IOS-derived model, COPD-SQ, and their combination for AO and COPD. Differences in area under the curve (AUC) were compared using DeLong's test. A total of 1858 participants with complete IOS parameters were analyzed. The IOS-derived model showed acceptable diagnostic accuracy for AO (AUC 0.826, 95% CI 0.808-0.844, sensitivity 67.4%, specificity 80.6%) and COPD (AUC 0.836, 95% CI 0.818-0.854, sensitivity 71.6%, specificity 78.1%) in this community-based cohort. The combination of the IOS-derived model and COPD-SQ demonstrated modestly higher diagnostic accuracy for AO (AUC 0.839 vs 0.826 for IOS-derived model or 0.784 for COPD-SQ, all P < 0.001) and COPD (AUC 0.851 vs 0.836 or 0.795, all P < 0.001) compared to either tool alone. In this community-recruited cohort with a relatively high prevalence of airflow limitation and COPD, the IOS-derived model exhibited good diagnostic performance and, when combined with the COPD-SQ, showed modestly improved accuracy for identifying AO and COPD compared to single-modality approaches. These findings support further evaluation of the model in unselected general populations and real-world primary care settings.