Fig. 2From: Sustained oxygenation improvement after first prone positioning is associated with liberation from mechanical ventilation and mortality in critically ill COVID-19 patients: a cohort studyCumulative incidence of liberation from mechanical ventilation. Cumulative incidence of liberation from mechanical ventilation (MV) over 28Â days after intubation. The four curves represent the cumulative incidence functions related to the quartiles of PaO2/FiO2 response to prone positioning referred to the multivariate model (Table 3)Back to article page