1318. Validation of Fluoroquinolone Resistance Score in Patients with Complicated Urinary Tract Infections
Session: Poster Abstract Session: Clinical Infectious Diseases: Urinary Tract Infections
Friday, October 28, 2016
Room: Poster Hall
  • FQRS IDWeek 2016 Poster Final.pdf (593.0 kB)
  • Background: The fluoroquinolone resistance score (FQRS) predicts the probability of fluoroquinolone resistance in gram-negative bloodstream isolates with good discrimination. The score is based on male sex (1 point), diabetes mellitus (1 point), residence at a skilled nursing facility (2 points), outpatient procedure within 1 month (3 points), and recent fluoroquinolone use (within 3 months, 5 points; and within 3-6 months, 3 points). This study aims to validate FQRS in complicated urinary tract infections (cUTI) and examine impact of extension of prior fluoroquinolone exposure to 12 months on model discrimination.

    Methods: Adults with cUTI at Palmetto Health Hospitals in Columbia, SC from April 1 to July 31, 2015 were prospectively identified. Multivariate logistic regression was used to examine association between prior fluoroquinolone use within 12 months of cUTI and fluoroquinolone resistance. Areas under receiver operating characteristic curves (AUC) were calculated to determine discrimination of FQRS models, using prior fluoroquinolone exposure up to 6 and 12 months, respectively.

    Results:  Among 238 unique patients with cUTI, 54 (23%) had fluoroquinolone-resistant urinary isolates. Overall, median age was 66 years, 87 (37%) were men and Escherichia coli (137; 58%) was the most common isolate. Prior fluoroquinolone use within 3 months (odds ratio [OR] 30.3, 95% confidence intervals [CI] 10.5-101.0, p<0.001) and within 3-12 months (OR 19.2, 95% CI 6.9-58.4, p<0.001) was independently associated with increased risk of cUTI due to fluoroquinolone-resistant isolates compared to no prior exposure (referent). AUC increased from 0.73 to 0.80 when prior fluoroquinolone use was extended from 6 to 12 months in FQRS. Patients with FQRS of 0, 2, 3 and 5 had estimated risk of fluoroquinolone-resistant urinary isolates of 6%, 19%, 31% and 60%, respectively.

    Conclusion: The study validates the use of FQRS in cUTI. Extension of prior fluoroquinolone exposure from 6 to 12 months improves discrimination of FQRS. Prediction of patient-specific risk of fluoroquinolone resistance using FQRS may improve selection of empirical antimicrobial therapy in cUTI and simplify antimicrobial management in low risk patients without indications for hospitalization.

    Ansal Shah, MD1, Julie Ann Justo, PharmD, MS, BCPS-AQ ID2, P. Brandon Bookstaver, PharmD, FCCP, BCPS, AAHIVP2, Joseph Kohn, PharmD, BCPS3, Helmut Albrecht, MD4 and Majdi Al-Hasan, MBBS4, (1)Department of Medicine, Division of Infectious Diseases, Palmetto Health/ University of South Carolina School of Medicine, Columbia, SC, (2)Department of Clinical Pharmacy and Outcomes Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC, (3)Palmetto Health Richland, Columbia, SC, (4)Department of Medicine, Division of Infectious Diseases, University of South Carolina School of Medicine, Columbia, SC


    A. Shah, None

    J. A. Justo, None

    P. B. Bookstaver, Allergan Pharmaceuticals: Scientific Advisor , Research grant

    J. Kohn, None

    H. Albrecht, None

    M. Al-Hasan, None

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