Statistical methods
The most basic statistical description of the studied
variables was then drawn.15 The following were calculated:
mean, standard deviation, median, minimum and
maximum. The distribution of each variable was then
confirmed with the normal distribution. In order to do
so, the Shapiro-Wilk normality test was applied. P >
0.05 was the level that a distribution was consistent
with the normal distribution.
Where there was normal distribution of both variables
in a pair, the t-Student test for dependent samples was
applied. However, for cases with no normal distribution
(for at least one of the two variables in a pair), the
non-parametric Wilcoxon test was used. The significant
level was P ≤ 0.05.