A Novel Risk Stratification Tool for Post-Urodynamic Urinary Tract Infection: Toward Individualized Antibiotic...

To develop and internally validate a risk prediction model for symptomatic urinary tract infection (UTI) following multichannel urodynamic studies (UDS), aimed at guiding individualized antibiotic prophylaxis.

This retrospective cohort study included 432 patients who underwent multichannel UDS between August 2021 and November 2024. The primary outcome was symptomatic, culture-confirmed UTI within 30 days post-UDS. Multivariable logistic regression identified independent predictors, which were incorporated into a point-based risk scoring system. Model performance was assessed using area under the receiver operating characteristic curve (AUC) for discrimination and calibration metrics including intercept, slope, and Brier score. Internal validation was conducted via 1000 bootstrap resamples.

Symptomatic UTI occurred in 46 patients (10.6%), including 15 (3.5%) with febrile UTI. Independent predictors included recent UTI (OR = 2.88), neurogenic lower urinary tract dysfunction (OR = 2.67), catheterization (OR = 2.45), and post-void residual > 100 mL (OR = 4.02). A 5-item risk score (range 0-14) was developed, categorizing patients into low (0-3), intermediate (4-6), and high-risk (≥ 7) groups with corresponding symptomatic UTI rates of 2.5%, 5.7%, and 25.4%; and febrile UTI rates of 1.0%, 2.3%, and 7.7%, respectively. The model demonstrated good discrimination (apparent AUC = 0.801, 95% CI: 0.733-0.869; optimism-corrected AUC = 0.773) and good calibration (optimism-corrected slope = 0.88; Brier score = 0.088).

We propose a novel and clinically applicable risk scoring system for predicting symptomatic UTI after UDS. This tool enables stratified prophylactic strategies, reduces unnecessary antibiotic use, and supports standardized, evidence-based infection risk management.