ROC Analysis Comparing Predictive Performance of Hb, CaO₂, and PaO₂ for Mortality in Patients with COPD.

Hemoglobin and CaO₂ showed similar discriminatory ability (AUC 0.735 and 0.732, respectively), whereas PaO₂ demonstrated poor predictive performance (AUC 0.532), indicating limited ability to discriminate mortality risk. These findings suggest that markers reflecting oxygen transport capacity provide greater prognostic information than PaO₂ alone.

COPD, chronic obstructive pulmonary disease; CaO₂, arterial oxygen content; Hb, hemoglobin; PaO₂, arterial partial pressure of oxygen.