Impact of Asymptomatic Bacteriuria (ASBU) Overtreatment During a Controlled Trial of Antimicrobial Stewardship (AS)

BACKGROUND: What are the clinical profiles, outcomes, and antimicrobial costs attributed to patients admitted with presumed urinary tract infection (UTI) but deemed to have “no infection” (NI) by infectious diseases (ID) MD reviewers? METHODS: We performed a review of a subset of patients entered into a randomized, controlled, AS trial that began 7.1.2015. Patients with UTI and 3 other ID syndromes were evaluated by ID MDs within 12–24 hours of receiving empirical antimicrobials. The ID MD designated patients as having NI when a patient lacked compatible symptoms, signs, and laboratory evidence to support a diagnosis of UTI. Patients with NI were tracked but not included in the study intervention to identify AS opportunities. RESULTS: Over 21 months 6,402 antimicrobial starts were entered into the AS study; 2,196 (34.3%) were UTI. Of these 564 (25.7%) were designated NI. The initial admission of 104 patients designated NI are the subject of this report. Four had possibly clinically significant UTI and were excluded. Of the remaining 100 the average age was 83.6 years, 80% were female and 50% were admitted with acute or chronic altered mental status (dementia, seizure, or stroke); Sixty-five % of urine cultures were positive. The mean Systemic Inflammatory Response Syndrome (SIRS) score was 0.6; the mean quick Sequential Organ Failure Assessment Score (qSOFA) score was 0.9. A mean 3.7 days of antimicrobials were prescribed during the admission; 3.2 additional days at discharge. Of the 100 NI patients followed (up to 21 months following study entry) 34% have died (all-cause), 49% had a subsequent episode of bacteriuria; the mean number of re-admissions per patient was 2.4(range 0–14) and 9% developed C. difficile infection (CDI). CONCLUSION: AS identified a subset of patients treated for UTI but determined by ID MDs as NI, as an elderly, predominantly female cohort, with a high incidence of new or pre-existing neurological conditions, subsequent bacteriuria, re-admission, and short -term mortality. Low SIRS and qSOFA scores in these patients supported a lack of clinically significant infection. AS programs should focus on early efforts to identify ASBU. Preservation of antimicrobial resources, antibiotic cost savings (estimated over 3 years to be $ 450,000), and avoidance of CDI are among the likely benefits. DISCLOSURES: All authors: No reported disclosures.