Predictive Accuracy of the ROX Index and HACOR Score for Non-Invasive Respiratory Support Failure in Critically Ill Patients: a Prospective Comparative Study
Keywords:
ROX Index, HACOR Score, High-Flow Nasal Cannula, Noninvasive Ventilation, Intubation.Abstract
Background: Early identification of noninvasive respiratory support failure may help avoid delayed intubation. This study compared the predictive performance of the ROX index and HACOR score in critically ill patients with acute hypoxemic respiratory failure.
Methods: This prospective comparative study included 200 adults receiving high-flow nasal cannula or noninvasive ventilation. ROX and HACOR were calculated at initiation and after 2 hours. The primary outcome was endotracheal intubation within 48 hours.
Results: Support failure occurred in 75 (37.5%) patients. At 2 hours, ROX was lower and HACOR higher among patients requiring intubation. ROX showed greater discrimination than HACOR (AUROC 0.705 vs 0.604; p=0.008). After adjustment, higher 2-hour ROX remained associated with lower odds of failure (adjusted OR 0.79 per point, 95% CI 0.69–0.92; p=0.002), whereas HACOR was not independently associated with outcome.
Conclusion: Two-hour ROX outperformed HACOR for predicting early support failure.




