Can the ROX index predict high‐flow nasal cannula failure in children under 2 with lower respiratory tract infection?

Objective This study evaluates the ROX index's accuracy in predicting the success or failure of high‐flow nasal cannula (HFNC) therapy in children under 2 years with acute respiratory failure (ARF) from lower respiratory tract infections. Methods From January 2018 to 2021 we conducted this multicenter retrospective cohort study, which included patients aged 2–24 months. We aimed to assess HFNC therapy outcomes as either success or failure. The analysis covered patient demographics, diagnoses, vital signs, and ROX index values at intervals from 0 to 48 h after initiating HFNC. We used bivariate analysis, repeated measures ANOVA, multivariate logistic regression, and the area under the receiver operating characteristic (AUC‐ROC) curve for statistical analysis. Results The study involved 529 patients from six centers, with 198 females (37%) and a median age of 9 months (IQR: 3–15 months). HFNC therapy failed in 38% of cases. We observed significant variability in failure rates across different centers and physicians (p