Emergency department urine culture stewardship and downstream outcomes: a covariate-adjusted biweekly interrupted time series analysis
James Howard Acuff, Ashwini Gotimukul, Ganesh Srinivasan Krishnamurthi, Todd Lasco, Armando Rafael Cecilio Leon Silva, D’Feau Jia Lieu, Kady Phe, Sabra L. Shay, Alfonso Francisco Siu, Nicholas Teran, Mayar Al MohajerAbstract
Background:
Emergency department (ED) urine culture stewardship may reduce low-value testing, but downstream effects on antibiotic use and postdischarge utilization remain uncertain.
Methods:
We evaluated an intervention in which an infectious diseases physician and microbiologist reviewed pyuric urinalysis-with-reflex encounters, assessed culture indications, and contacted clinicians to recommend cancellation when absent. Adult ED encounters from February–July 2025 to September 2025-February 2026 were included; August was washout. Outcomes were urinalysis with reflex within 24 hours, urine culture within 24 hours, antibiotic days of therapy (DOT) per 100 patient-days, length of stay (LOS), and 30-day ED revisit among ED discharges. We fit biweekly interrupted time series models.
Results:
Among 17,621 encounters, the intervention was associated with lower postintervention slopes for urinalysis with reflex within 24 hours (−0.5 percentage points per biweekly period; 95% CI, −0.9 to −0.1) and urine culture within 24 hours (−0.2 percentage points; 95% CI, −0.4 to −0.0). DOT showed no sustained change (postintervention slope change, 0.00; 95% CI, −0.23 to 0.24). LOS showed a lower postintervention slope (−0.05 d; 95% CI, −0.08 to −0.02). Thirty-day ED revisit showed a higher postintervention slope (0.8 percentage points; 95% CI, 0.3 to 1.3).
Conclusions:
The intervention reduced urinary testing but did not reduce antibiotic DOT and was associated with increased 30-day ED revisit. Diagnostic stewardship in the ED may need to be paired with antimicrobial stewardship and prospective safety monitoring.