Statistics
Statistical analyses were performed using SPSS version 22.0 statistical
software package (IBM SPSS Statistics, USA). First normality tests for
continuous variables were performed and as all of the continuous
variables were distributed non-normally the results were given as median
[inter-quartile range(IQR)]. The chi-square and Mann-Whitney U tests
were used to compare nonparametric values. For the risk analysis of
drop-outs variables were selected if the p value was less than 0.20 in
the univariate analysis and included in multivariate analysis. Odds
ratios (ORs) with relevant 95% confidence intervals (CIs) were
calculated to evaluate potential associations. Values of P<.05
were accepted as significant.