150 How Many Urines Had We Been Culturing Way Too Many......

Introduction/Objective Urinalyses (UA) are frequently ordered to diagnose urinary tract infections (UTIs), but a positive UA may indicate asymptomatic bacteriuria as well as a true UTI. To help ensure that urine cultures are always completed for UAs that are suggestive of infection, many laboratories use reflex algorithms to facilitate automatic ordering of urine culture based on the biochemical and/or microscopic results. Currently, criteria for urinalysis with reflex to culture (UARC) vary significantly between institutions, with less stringent criteria having clinical, operational and financial impacts. Historically, the reflex criteria in our health system were: positive leukocyte esterase or positive nitrite or moderate or many bactria or > 10 WBC count. In August, 2023, our health system implemented a new evidence-based criteria for urine cultures: WBC count of > 10 cells (>5 for pediatric patients <24 months).The objective of this study was to assess the clinical, operational and financial impacts of the UARC criteria change. Methods/Case Report We conducted a retrospective cohort study using Electronic Health Record (EHR) data at a health system consisting of 3 hospitals, an outpatient lab and a freestanding Emergency Department comparing the pre-implementation period of 12/15/22 - 8/14/2023 to the post implementation period of 8/15/2023 - 4/15/2024. We assessed clinical impact by comparing: 1) the daily percentage of UA reflexed to culture, overall (from inpatient/ED/observations/ambulatory settings) and in the ambulatory setting only between the two periods using interrupted time-series 2) the median length of stay (inpatient/observation visits) 3) the rate of UTIs identified based on ICD-10 discharge diagnoses We assessed operational impact using interrupted time-series by comparing the diagnostic efficacy of the reflex criteria (daily proportion of urine cultures with >100,000 CFU/mL bacterial growth) before vs after the change in criteria. Finally, we assessed financial impact by comparing the effect of the change on the cost of urine cultures performed on hospitalized patients before vs. after the change in UARC criteria. Results Our results showed that the percentage of UA that reflexed to culture from UARC orders decreased by 37% (p < 0.001) for orders from all settings and 35% for orders ambulatory setting after the criteria change. The length of stay did not change significantly between the pre and post time periods. The percentage of daily UTI diagnosis decreased but this change was not significant after adjusting for temporal trend. The culture positive rate of all cultures reflexed from UARC increased by 26% (p < 0.001) after the change reflecting a more efficient testing operation. Furthermore, the UARC criteria change led to a 31% ($65,000) decrease in the cost associated with urine cultures on inpatient visits. Conclusion Our study demonstrated a favorable clinical, operational and financial impact of limiting the criteria for UARC. In using our resources wisely, this change freed up laboratory staff to focus on more meaningful laboratory tests and saved costs related to culture supplies and labor. The results also show that reflex testing offers convenience to clinicians improves standard of care, yet reflex criteria need to be evaluated periodically to endure clinical, operational and financial appropriateness. This study is a testament to the fact that the laboratory can successfully implement evidence-based diagnostic stewardship in collaboration with multidisciplinary stakeholders and extract, analyze and review the data to show the impact.