Statistical analysis
Statistical analyses were performed by using IBM SPSS Statistics for Windows, Version 25.0. (IBM Corp. Released 2017. Armonk, NY) and R software, version 3.5.2, package: nparLD (R Foundation for Statistical Computing, Vienna, Austria; https://r-project.org).
Normally distributed continuous variables were displayed as mean ± standard deviation, non-normally distributed continuous variables were displayed as median (minimum–maximum). Repeated measures ANOVA was used for normally distributed variables. When an interaction (interaction represents that the changes of parameters obtained at hospital admission and follow-up were different between the two groups) was found to be significant, paired t-test, two independent samples t-test, and analysis of covariance were performed. For the evaluation of non-normally distributed variables, the Brunner and Langer method (F1-LD-F1 model) was used. When an interaction was found to be significant, Mann–Whitney U test and Wilcoxon test were performed. Receiver Operating Characteristic (ROC) analysis was used for the assessment of the laboratory values obtained at the time of the first chest CT to predict the changes in the CT scores. Categorical variables were compared between the two groups of patients using the chi-square test and Fisher’s exact test. Spearman’s Rho analysis was used to evaluate the relationship between L/S and liver function tests.