Statistical Analysis
Statistical analyses were
performed by a biostatistician using SPSS Statistics version 21.0
(IBM). The normality of data analyzed by using Kolmogorov-Smirnov. The
descriptive statistics were reported as mean± standart deviation,
medians, and ranges (min-max). Independent Sample T-Test and Mann
Whitney U test, these tests are used to see there or not the average
difference between the two independent groups, accordingly in parametric
and nonparametric variables. The relationship between two sets of data
was analyzed by Spearman’s rank correlation test. OS analyses of the
groups were evaluated with Kaplan-Meier curves, and differences were
tested with a log-rank test. All comparative tests were 2-tailed, and a
p -value of less than 0.05 was considered to be statistically
significant. Effects of covariates on possibility of survivals in
univariate analysis are reported as hazard ratio (HR) with 95%
confidence interval (CI).