Data analyses
Normality of variables was determined by Shapiro-Wilkins test.
Categorical variables are summarized as frequencies and percentages and
continuous variables as means ± standard deviations (SD), or as median
with interquarter range when data were skewed. Categorical outcomes were
compared using either χ2 and continuous outcomes by
Student’s T test or by the Wilcoxon rank-sum nonparametric test.
Actuarial survival was studied by the Kaplan Meier method, and log-rank
test used in the comparison of study groups. Cox proportional hazard
model was constructed in order to account for variables related to
post-transplant long-term survival. Hazard ratios with corresponding
confidence intervals were determined. The level of significance was
determined when the P value was less than 0.05. All analyses were
performed using JMP for SAS® (Cary, NC, USA) statistical software
version 14.