STATISTICAL ANALYSIS
Statistical analysis was performed using SPSS Version 16 software
(IBM,
Armonk, New York). Data were expressed as median and range
(minimum-maximum) for numerical data, number and percentage for
categorical data. Comparisons between groups were calculated using
nonparametric Mann–Whitney test for numerical data and χ2 test for
categorical data. Survival analysis was done using Kaplan-Meier log-rank
univariate analysis.