Statistical Methods
The characteristics of the study patients were expressed as mean or median, as appropriate for categorical variables, percentages and variables with continuity. Mann-Whitney U-test and Kruskal-Wallis test were used for comparing median variables between groups and independent samples t -test and one-way ANOVA tests were used for comparing parametric variables. For comparing categorical data, Chi-square and Fisher’s exact test was used. Cox regression analysis was used to investigate the risk factors for the development of urinary tract infection. For all statistical analysis, p value <0.05 was considered significant. All data are analyzed with SPSS (version 20.0; SPSS Inc, Chicago, IL) statistical package.