Statistical method
Prognosis
REGRESSION
We used IBM SPSS version 22.0 for the statistical analysis. Continuous data are presented as the median with range. Categorical variables were compared by Pearson’s chi-square or Fisher’s exact as appropriate. Continuous variables were compared by the Mann–Whitney U test (nonparametric method). Multivariate analysis for risk factors for mortality was conducted using a logistic regression model. Prognosis and survival curves were generated by the Kaplan–Meier method. Comparative analyses were conducted by log-rank and Cox regression. Significance was defined as p < 0.05.