Statistical analysis
Continuous numeric variables were expressed as mean ± SD or medians (IQR), and compared with a two-sample t test and one-way analysis of variance (for normally distributed data), or Mann-Whitney test and Kruskal-Wallis test (for non-normal distribution of data). Categorical variables were expressed as frequency number (%), and compared using χ 2 test or Fisher’s exact test. Survival curves were obtained by the Kaplan-Meier analysis and compared using log-rank test. Receiver operator characteristics (ROC) analysis was undertaken to compute the best predictive threshold of significant biomarker elevation for mortality prediction. Estimations of mortality predictors were performed using univariate and multivariate Cox regression models. All statistical calculations were performed using MedCalc Statistical Software version 19.2 (MedCalc Software, Ostend, Belgium; http://www.medcalc.org; 2020).