Statistical analysis
Quantitative data are expressed as mean ± standard deviation and were
compared using the two-tailed t test. Categorical data are expressed as
percentages and were compared using the chi-square test. Comparisons of
events by groups were made by Kaplan–Meier analysis and the log-rank
test. Predictors of delayed PE/PT were analysed by univariate and
subsequent multivariate Cox regression analyses. The results were
expressed as hazard ratios (HRs) with 95% confidence intervals (CIs).
P<0.05 was considered statistically significant. All
statistical analyses were performed using SPSS version 23.0.