2.7. Statistical Analysis

Continuous variables are expressed as the mean ± standard deviation and were compared using the Mann–Whitney U test. Categorical variables, such as the preadmission demographics, were compared using Fisher's exact test to assess the association of different variables with mortality logistic regression analyses that were performed. The discriminatory power of the early driving pressure change for predicting mortality was assessed by calculating the area under the receiver operating characteristic (ROC) curve (AUC). A cut-off value was calculated based on the Youden index. All statistical analyses for this study were performed in Prism 8 (GraphPad Software Inc.) and in JMP 14.2 (SAS Institute Inc., Cary, NC, USA). The p values are two-tailed, and values <0.05 are considered statistically significant.