Supplementary Material for: Early Variation of Respiratory Indexes to Predict Death or ICU Admission in Severe Acute Respiratory Syndrome Coronavirus-2-Related Respiratory Failure

Background: In severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-related respiratory failure, the prognostic value of clinically based or blood-gas-based respiratory indexes is unclear. Objectives: We aimed to assess the prognostic value of Respiratory Index (RI, oxygen saturation [SpO2]/respiratory rate [RR]), RR-oxygenation index (ROX, SpO2/fraction of inspired oxygen [FiO2]/RR), partial pressure of oxygen (PaO2)/FiO2 ratio (P/F), or standard PaO2/FiO2 ratio (STP/F) at admission and of their variation during hospitalization in SARS-CoV-2-related respiratory failure. Methods: In 100 consecutive patients hospitalized due to SARS-CoV-2-related respiratory failure, we assessed the association of RI, ROX, P/F and STP/F, and death; secondary outcome was the composite of 7-day death or intensive care unit (ICU) admission. Results: ROX STP/F (HR 1.05, 95% CI: 1.01–1.08) during hospitalization was associated with 7-day death or ICU admission. Conclusions: In patients with SARS-CoV-2-related respiratory failure, easy-to-calculate clinically based respiratory indexes at admission and their variation during hospital stay can be used to assess and monitor the risk for death or ICU admission.