Statistical Analysis
Continuous variables were presented through means, standard deviations, and medians, whereas categorical variables were presented as proportions. Parameters with normal distribution were compared by independent groups (independent samples) t-test whereas for the parameters without normal distribution Mann Whitney U test was used. Spearman’s rho correlation analysis was used to analyze the relationship between two continuous variables that do not distributed normally. Pearson’s correlation analysis was used in variables that distributed normally. The χ² test was used for categorical variables and expressed as observation counts (and percentages). Statistical significance was accepted when two-sided p value was lower than 0.05. Statistical analysis was performed using the MedCalc Statistical Software version 12.7.7 (MedCalc Software bvba, Ostend, Belgium; http://www.medcalc.org; 2013).