2.7 Statistics analysis
SPSS version 23 software (SPSS Inc., Chicago, Illinois) was used for
statistical analysis. Data is expressed as means ± standard deviation
for continuous variables and as frequencies and percentages for
categorical variables. Baseline characteristics and outcomes were
compared using the chi-square test for categorical variables and the
T-student test for continuous variables. Cox regression analysis was
used to calculate the hazard ratio (HR) and 95% confidence intervals
(CI) of events. Kaplan–Meier survival function and the log-rank test
were used to compare the survival distributions. A value of
p<0.05 was considered statistically significant.
RESULTS