Urine culture guided antibiotic interventions: A pharmacist driven antimicrobial stewardship effort in the ED

Antibiotics are overprescribed for abnormal urine tests including asymptomatic bacteriuria (AB), contributing to rising antimicrobial resistance rates. Pharmacists reviewed urine cultures daily from emergency department (ED) encounters to assess antibiotic appropriateness. We studied antibiotic prescribing practices and assessed compliance to national guidelines, correlations with urine analysis (UA) components, and opportunities for antimicrobial stewardship in the ED.

This quality improvement project (QIP) was a prospective cohort study at a community hospital ED, with data collected from finalized urine cultures resulting October 30, 2014 through January 5, 2015. Analyses were conducted using Chi-squared and Fisher Exact tests and stepwise multiple logistic regression.

Urine cultures from 457 encounters were reviewed, of which 136 met the inclusion criteria as non-pregnant and asymptomatic for urinary tract infection (UTI). 43% of 136 patients were treated with antibiotics, for a total of 426 antibiotic days. Pharmacist interventions for these patients resulted in 122/426 (29%) of potential antibiotic days saved. Factors found to significantly increase the odds of antibiotic prescribing in asymptomatic patients included presence of leukocyte esterase (OR=4.5, 95% CI: 1.2-17.2; p=0.03) or nitrites (OR=10.8, 95% CI: 1.7-68.1; p=0.01) in the urine and age≥75 (OR=3.5, 95% CI: 1.2-9.6, p=0.02).

Pharmacist intervention in discontinuing or modifying antibiotics for asymptomatic patients with urine cultures reduced unnecessary antibiotic exposure and was a first step in antimicrobial stewardship efforts in the ED. Future work includes limiting urine tests and subsequent antibiotic therapy for non-pregnant asymptomatic patients.