Effect of transitioning from sterile to clean urinary catheterisation on catheter-associated urinary tract infections and sustainability: a pre–post study in a Dutch university hospital

Introduction Bladder catheterisation is one of the most commonly performed medical procedures worldwide in hospitals. Although traditionally performed as a sterile procedure to prevent infections, it incurs a considerable carbon footprint and substantial healthcare costs. This study aimed to assess whether adopting clean bladder catheterisation as standard hospital practice is non-inferior to sterile catheterisation regarding the occurrence of catheter-associated urinary tract infections (CAUTIs), and to evaluate the carbon footprint of catheterisation sets. Methods This retrospective observational non-inferiority study compared the proportion of patients with a suspected CAUTI during a 6-month sterile catheterisation phase and a 6-month clean catheterisation phase. The primary outcome was the proportion of CAUTIs, with secondary outcomes including positive urine cultures, cultured microorganisms and carbon footprint. Non-inferiority of clean catheterisation was assessed using multivariable logistic regression, reporting risk differences (RDs) and 95% CIs. Non-inferiority was concluded when the upper bound of the 95% CI did not exceed the non-inferiority margin of 0.5 percentage point. Interrupted time series (ITS) analysis assessed time trends, and the carbon footprint was evaluated using life-cycle assessment. Results Among 3293 catheterised patients, 3.8% (62/1647) in the sterile phase and 3.3% (55/1646) in the clean phase met the criteria for a CAUTI (adjusted RD −0.44% (95% CI −1.4% to 0.5%)). ITS analysis showed no significant change in CAUTI trends following implementation. Positive urine cultures were found in 13.1% (216/1647) and 13.1% (215/1646) of patients in the sterile and clean catheterisation phases (adjusted RD 0.30% (95% CI −2.4% to 1.7%). The carbon footprint of the clean catheterisation set was 70.7%–82.3% lower compared with the sterile sets. Conclusion Clean bladder catheterisation was non-inferior to sterile catheterisation in suspected CAUTI rates and significantly reduced the carbon footprint. Our findings suggest that clean catheterisation may be considered as a safe alternative default practice.