Additional file 1 of ROX index performance to predict high-flow nasal oxygen outcome in Covid-19 related hypoxemic acute respiratory failure

Additional file 1: Figure S1. Receiver operating characteristic curves for HFNO failure within 28 days at different times after HFNO initiation. HFNO: high-flow nasal oxygen therapy; ROC: receiver operating characteristic; H0: ROC curve at the time of HFNO initiation; H12:12 hours after HFNO initiation; H18: 18 hours after HFNO initiation; H24:24 hours after HFNO initiation. Figure S2. Rox index performance to predict the risk of HFNO failure at different times after HFNO initiation. HFNO: high-flow nasal oxygen therapy; red line gives proportion of patients in the HFNO failure group with a ROX index ≤ a chosen cut-off value; black line gives proportion of patients in the HFNO success group with a ROX index ≤ a chosen cut-off value. For example: at H6, using a Rox index of ≤8.50 as cut-off would identify 90% of patients with HFNO failure after H6, whereas this cut-off would identify only 38% of patients with HFNO success after H6, avoiding intubation. Figure S3. Incidence of HFNO failure within 7 days after HFNO initiation. HFNO: high-flow nasal oxygen therapy. Table S4. Conditions of intubation and clinical respiratory parameters in all intubated patients and according to hemodynamic status. HFNO: high-flow nasal oxygen therapy; FiO2: fraction of inspired oxygen; SpO2: pulse oxygen saturation; RR: respiratory rate; values are expressed as n (%) or median (Q1-Q3). Table S5. Rox index at H0, HFNO outcome and duration according to each ICU center. HFNO: high-flow nasal oxygen therapy; ICU: intensive care unit; values are expressed as n (%) or median (Q1-Q3); *= logistic regression unless stated otherwise; **= Kruskall-Wallis’s test.