Statistical Methods
Statistical analyses were performed using SPSS software (version 22; IBM SPSS Inc., Chicago, IL, USA). Unless otherwise specified, data in the results section are shown as median ± standard deviation. Chi-square test was used to assess associations between nominal variables. In cases with expected cell counts below 5, p-values of the Fisher’s exact value was reported. Moreover, the unpaired student’s t-test was used to compare means of normally distributed variables of two independent groups. GraphPad Prism 7 (GraphPad Software Inc., California, USA) was used for graphical display of all figures in this manuscript.
RESULTS