Data Sheet 1_Quantitative CT features for COPD classification and GOLD spirometric severity assessment: a single-center model-development study.docx

Model performance is reported as apparent performance because internal and external validation were not performed.</p>Results<p>Compared with control participants, COPD participants had smaller airway lumen area, higher wall-to-diameter ratio (T/D), higher wall area percentage (WA%), and higher LAA%. Mean wall thickness did not differ significantly, indicating that the group difference mainly reflected lumen narrowing rather than wall thickening.

Emphysema extent was associated with lower FEV1/FVC and FEV1%pred. Sparse-type bronchial morphology was associated with COPD in multivariable analysis (OR 28.6, 95% CI 6.7–149.8), but the wide confidence interval and the need for reproducible operational validation require cautious interpretation. The combined clinical-CT development models achieved apparent AUCs of 0.906 for COPD classification and 0.859 for classification of severe airflow obstruction.</p>Conclusion<p>Quantitative HRCT emphysema and visible-airway measurements were associated with COPD status and spirometric airflow obstruction.

The models should be regarded as single-center development models, and the bronchial-tree morphology finding should be interpreted as hypothesis-generating until reproducibility, calibration, incremental value, and external validation are demonstrated.</p>