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.