Continuously available ratio of SpO2/FiO2serves as a noninvasive prognostic marker for intensive care patients with COVID-19

Rationale Oxygen saturation to fraction of inspired oxygen ratio (SpO(2)/FiO(2)) has been described as potential predictor of poor outcome for COVID-19, without considering its time-varying behavior though. Methods Prognostic value of SpO(2)/FiO(2)was evaluated by jointly modeling the longitudinal responses of SpO(2)/FiO(2)and time-to-event data retrieved from 280 severe and critically ill (intensive care) patients with COVID-19. Results A sharply decrease of SpO(2)/FiO(2)from the first to second measurement for non-survivors was observed, and a strong association between square root SpO(2)/FiO(2)and mortality risk was demonstrated, with a unit decrease in the marker corresponding to 1.82-fold increase in mortality risk (95% CI: 1.56-2.13). Conclusions The current study suggested that SpO(2)/FiO(2)could serve as a non-invasive prognostic marker to facilitate early adjustment for treatment, thus improving overall survival.