Abstract
BACKGROUND: Antibiotic treatment for asymptomatic bacteriuria (ASB) is prevalent but often contrary to published guidelines. OBJECTIVE: To evaluate risk factors for treatment of ASB. DESIGN: Retrospective observational study. SETTING: A tertiary academic hospital, county hospital, and community hospital. PATIENTS: Hospitalized adults with bacteriuria. METHODS: Patients without documented symptoms of urinary tract infection per Infectious Diseases Society of America (IDSA) criteria were classified as ASB. We examined ASB treatment risk factors as well as broad-spectrum antibiotic usage and quantified diagnostic concordance between IDSA and National Healthcare Safety Network criteria. RESULTS: Among 300 patients with bacteriuria, ASB was present in 71% by IDSA criteria. By National Healthcare Safety Network criteria, 71% of patients had ASB; within-patient diagnostic concordance with IDSA was moderate (kappa, 0.52). After excluding those given antibiotics for nonurinary indications, antibiotics were given to 38% (62/164) with ASB. Factors significantly associated with ASB treatment were elevated urine white cell count (65 vs 24 white blood cells per high-powered field, P<.01), hospital identity (hospital C vs A, odds ratio, 0.34 [95% CI, 0.14-0.80], P =.01), presence of leukocyte esterase (5.48 [2.35-12.79], P<.01), presence of nitrites (2.45 [1.11-5.41], P=.03), and Escherichia coli on culture (2.4 [1.2-4.7], P=.01). Of patients treated for ASB, broad-spectrum antibiotics were used in 84%. CONCLUSIONS: ASB treatment was prevalent across settings and contributed to broad-spectrum antibiotic use. Associating abnormal urinalysis results with the need for antibiotic treatment regardless of symptoms may drive unnecessary antibiotic use.