Statistical analysis
Statistical analysis was performed using ”Statistical Package for Social Sciences 22.0 software (SPSS 22.0 for MAC)”. Descriptive statistics were presented as mean ± standard deviation, frequency and percentages. Shapiro-Wilk test was used to determine whether the data showed normal distribution. It was observed that all the parameters we examined conformed to normal distribution. Student’s t-test (T test in independent groups) was used to compare normally distributed continuous variables between the control and patient groups before initial TURBT. Mann-Whitney U test was used to compare not normally distributed continuous variables between the control and patient groups before initial TURBT. The comparison between the patient and control groups for sex was performed using the chi-square test. In the patient group, repeated measures analysis of variance (ANOVA) was used to compare variables between the preoperative, postoperative first control and postoperative second control. When appropriate, a Bonferroni t-test was used as a post hoc test. P<0.05 was defined as the statistical significance level.