Do hydrophilic catheters reduce the incidence of symptomatic urinary tract infections? – An Update

Objective: To test whether selection bias may have affected the reported effect estimate for hydrophilic catheters (Risk Difference, RD –0.06; 95%CI: -0.35 to 0.22; p = 0.67) to reduce symptomatic urinary tract infections (UTI) frequency. Method: Trial adjusted, simulated comparator trial (SCT) based I2 test for single randomised controlled trials, using revised I2 threshold limits. Result: A baseline covariate imbalance, either due to chance or due to selection bias was established, being equivalent to selection bias level = B% 0-30 (Bias category = 1). This level suggests that 0-39% of (0 – 18 of the total 45) subjects were non-randomly allocated in favour of one treatment group above the other. Conclusion: The effect estimate reported by the tested trial does not suggest any significant differences in URI frequency for hydrophilic catheters above the control intervention. The selection bias level, estimated by use of the trial adjusted, SCT based I2 test for single RCTs (B% 0-30) appears to be too low in order to have affected the reported effect estimate. In line with new findings, this report updates previous report to the same RCT: EBSM Volume 1, Issue 1, 2025 Pages 49-50, DOI: 10.5281/zenodo.17569874.