Antibiotic prescribing for asymptomatic bacteriuria (ASB) remains a major source of unnecessary prescribing; high occurrence of urine testing and ambiguity in interpretation of results may be contributing factors. Our objective was to characterize the frequency of antibiotic use for ASB by type of urine test ordered and evaluate concordance between test results and antibiotic use.
We conducted a retrospective cross-sectional study of patients (age ≥ 18) hospitalized >24 hours on medical and surgical services at our institution between January and March 2015. Patients with orders for microscopy/urine analysis with reflex to culture or adult urinary tract infection (UTI) panel (dipstick with reflex to culture) were included. We considered individuals’ first hospitalization and excluded pregnant, urological, and transplant patients. Patients were compared across order type (Chi-square test) for temperature ≥ 36◦C (“fever”), white blood cell (WBC) count above 11,000, source of urine sample, documentation of a clinical indication of UTI (i.e., abdominal pain, burning or pain with urination, urgency, hesitancy or frequency), and initiation of antimicrobials.
A total of 2598 patients were identified for inclusion; 2137 (82.3%) received an adult UTI panel, and the remaining 461 (17.7%) received microscopy and/or urine analysis testing. Fever or elevated WBC was present in 6.2% of adult UTI panel versus 5.9% of microscopy/urine analysis patients (p=0.77). The proportion of patients receiving ≥ 1 antibiotic among those without fever or elevated WBC was similar among adult UTI panel (26.1%) versus microscopy/urine analysis patients (27.2%; p=0.64). Within the adult UTI panel group, 64.6% had test results not clearly indicative of a UTI; of those patients, 34.1% received antibiotic therapy.
Conclusion: At our institution, potentially unnecessary antibiotic use was similar among patients receiving the adult UTI panel and those with microscopy/urine analysis. Overall, prescribing of antibiotics was common among patients where diagnostic results were not indicative of UTI. We plan to use this information to identify areas for intervention and thereby lessen inappropriate antibiotic use.
A. Brady, None
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E. Bonura, None
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