De-implementation strategy to reduce overtreatment of asymptomatic bacteriuria in the emergency department: a stepped-wedge cluster randomised trial

Background: Asymptomatic bacteriuria (ASB) is the presence of bacteria in the urine of patients without symptoms of a urinary tract infection. Generally, treating ASB is not beneficial. Objective: We aimed to reduce overtreatment of ASB in the emergency department (ED) through a multifaceted de-implementation strategy. Design: A stepped-wedge cluster randomised trial. Methods: We performed our study in five EDs in the Netherlands from December 2020 to December 2021. Adult patients with urine cultures obtained during ED presentation were screened for inclusion and we excluded patients with indications for antibiotic therapy. The de-implementation strategy included education, reminders and competitive feedback on baseline results. The primary endpoint was patients with ASB treated with antibiotics. Secondary endpoints included the treatment duration and the number of urine tests ordered (urinalyses and urine cultures) in the ED per 1000 adult patients. Results: In total, 6837 urine cultures were screened. ASB was present in 224/3289 (7%) and 201/3548 (6%) patients, from whom 65/224 (29%) and 46/201 (23%) were inappropriately treated with antibiotics in the baseline and intervention period, respectively (adjusted odds ratio 1.20, 95% CI 0.56-2.62, p = 0.65). The number of urinalyses ordered decreased from 182 to 153 per 1000 patients (incidence rate difference -29.10, 95% CI -46.36 to -11.78, p < 0.001). Further, the treatment duration was shortened for patients with ASB in the intervention period (baseline period: 7.98 days (standard deviation (SD) 4.31) vs 5.79 days (SD 3.33), p = 0.006). Conclusion: Diagnostic stewardship by our de-implementation strategy reduced the number of urinalyses ordered and treatment duration in the ED, but we found no significant reduction in overtreatment of ASB.