A stepwise antimicrobial and diagnostic stewardship intervention for ordering urine cultures in Saudi Arabia: a quasi-experimental study.

INTRODUCTION

Inappropriate ordering of urine culture tests can lead to unnecessary antibiotic use and antimicrobial resistance. We evaluated the implementation of a stepwise stewardship intervention, with a focus on the appropriateness of urine culture orders and antibiotic use.

METHODS

We conducted a quasi-experimental study from August 2021 to June 2023 at a teaching hospital in Riyadh, Saudi Arabia. We included adult patients with urine culture orders. A stepwise stewardship intervention was implemented in two phases. In the first phase, a clinical decision support (CDS) tool was introduced in February 2022. In the second phase, a reflex urine culture was implemented in January 2023. Our outcomes were the percentage of inappropriate urine cultures ordered and antibiotic use. Outcomes were assessed at baseline, after the CDS intervention, and after the reflex urine culture intervention. We used multivariable logistic regression to estimate the adjusted odds ratio, controlling for potential confounding variables.

RESULTS

During the pre-intervention period, the percentage of inappropriate urine culture orders was 41.6%. Following the implementation of the first intervention-CDS-the percentage decreased to 36.4%. Subsequently, with the addition of reflex urine culture in the second phase of the stepwise intervention, the percentage further decreased to 28.6% (p value=<0.001). The stepwise intervention was associated with 15% lower odds of inappropriate urine culture ordering (adjOR 0.85; 95%CI 0. 0.69 - 0.90; p = 0.027). A significant reduction in unnecessary antibiotics was observed across the three phases: 85.7% pre-intervention, 72.9% post-CDS, and 25% post-CDS and reflex urine culture (p <0.0001). The stepwise intervention was associated with 75% lower odds in unnecessary antibiotic use (aOR 0.25; 95% CI 0.17 - 0.37, p <0.001).

CONCLUSIONS

This stepwise intervention suggests that each intervention contributed incrementally to decreasing unnecessary antibiotic use. However, the reduction in inappropriate urine culture request was primarily driven by the implementation of the CDS intervention.