2.3 Statistical analysis
The data was analyzed using the Statistical Analysis System® software program, version 9.4 (SAS Institute, Inc., Cary, NC, U.S.A.). Continuous variables were expressed as medians and interquartile ranges (IQRs). Continuous data from multiple groups were compared using the Mann-Whitney U test with the Holm’s correction. A p value < 0.05 was considered statistically significant.
The risk factors for infection with mortality were analyzed using a logistic regression model. All of the variables with p< 0.10 in the univariate analysis were included to construct the multivariate analysis. Odds ratios (ORs) and 95%confidence intervals (CIs) were calculated.