The routine use of prophylactic antibiotics in flexible cystoscopy remains controversial due to the generally low risk of post-procedural urinary tract infection (UTI). This study aimed to evaluate the effectiveness of prophylactic antibiotics in preventing post-procedure UTI and to identify risk factors associated with its occurrence.

This retrospective cohort study was conducted from July to December 2024 in single center, including patients who underwent flexible cystoscopy. Patients were categorized into two groups based on whether prophylactic antibiotics were administered after the procedure: the antibiotic group and the non-antibiotic group. The primary outcome was the incidence of post-procedure UTI, defined as the presence of UTI-related symptoms leading to either an outpatient clinic visit or hospital admission within one month following the procedure. Univariate analysis using Chi-square or Fisher’s exact test was used to evaluate potential associations between clinical variables and UTI occurrence. Multivariate logistic regression analysis was performed to identify independent risk factors after adjusting for confounding variables.

A total of 478 patients who underwent flexible cystoscopy were included in the study. Among them, 106 patients (22.2%) received post-procedure prophylactic antibiotics. The overall incidence of post-procedure UTI was 4.2% (20/478). Among the 20 patients who developed post-procedure UTI, the male to female ratio was 1:1, with 6 patients(30%) requiring hospitalization,. No significant difference in UTI incidence was found between patients who received prophylactic antibiotics and those who did not (5.7% vs. 3.8%, p = 0.56; adjusted OR: 1.23, 95% CI: 0.41–3.71, p = 0.711). Univariate analysis revealed that a history of recurrent UTI (p = 0.034) was associated with higher UTI rates. In multivariate logistic regression, three factors were independently associated with increased UTI risk: CKD ≥ stage 3 (OR: 4.64, p = 0.014), recurrent UTI (OR: 6.82, p = 0.024), and urinary retention (OR: 6.52, p = 0.038). Prophylactic antibiotic use was not significantly protective against post-procedure UTI, even after adjusting for physician prescribing patterns.

Routine prophylactic antibiotic administration of flexible cystoscopy does not significantly reduce the risk of post-procedure urinary tract infections. Given the low overall UTI rate and the lack of protective effect, antibiotic use should be reserved for patients with specific risk factors rather than administered universally.