Fig. 3From: ROX index versus HACOR scale in predicting success and failure of high-flow nasal cannula in the emergency department for patients with acute hypoxemic respiratory failure: a prospective observational studySurvival function for high-flow nasal cannula failure of patients with the ROX index lower than 4.88 (blue line) compared to those with the index equal to or higher than 4.88 (red line) at 1 h (A), 2 h (B), and 6 h (C). The p-value for log rank test comparing survival functions between the groups at the ROX index cut-point of 4.88 = 0.001 (A) and < 0.001 (B and C)Back to article page