STATISTICAL ANALYSIS
The Statistical Package for the Social Sciences (SPSS) version 21.0 was used for the statistical analyses. The categorical variables are presented as frequencies and percentages. The continuous variables were assessed by Kolmogorov-Smirnov test and histograms to find out if their distributions were normal or not. The normally distributed numerical parameters were compared by student’s t-test in two groups, while those with non-normal distributions were analyzed by Mann-Whitney U test. The categorical variables were compared by Chi-squares or Fisher’s Exact tests where appropriate. The strength of the relationship between the two variables was carried out using Spearman’s or Pearson correlation coefficient. A p-value < 0.05 was considered as statistically significant.