Patterns of Antimicrobial Use in an Outpatient Hemodialysis Unit

Abstract

Background: Hemodialysis (HD) patients are at high risk for infections, including those caused by multi-drug resistant organisms (MDROs). Since antimicrobial exposure is the main risk factor for the emergence of MDROs, minimizing inappropriate antimicrobial use is imperative. Objectives: To optimize antimicrobial use, it is first important to understand patterns of antimicrobial prescribing in this setting. The objectives of this study were to: (1) measure antimicrobial use, and (2) describe antimicrobial prescribing patterns, among patients receiving outpatient HD at the University Health Network. Methods: A retrospective observational cohort study was performed in an outpatient HD unit at an academic centre from February 1 – April 30, 2017. Eligible patients included adults who were prescribed at least one oral or intravenous (IV) antimicrobial by a hospital or community prescriber. Data were retrieved from the HD unit infection control database and analyzed using descriptive statistics. The primary outcome was total antimicrobial days of therapy (DOT) per 1000 patient-days. Secondary outcomes were antimicrobial prescriptions characterized by type of antimicrobial, purpose, indication, route, and prescriber type. Results: A total of 53 patients were eligible for inclusion and 75 antimicrobial prescriptions were included for analysis. Over the 3-month study period, antimicrobial use was 27.5 DOTs/1000 patient-days. Antimicrobial use occurred in 53 (16%) of 330 total outpatient HD patients. The most common indication for antimicrobial therapy was skin and soft tissue infection, followed by bloodstream infection and respiratory tract infection. Fluoroquinolones were the most frequently prescribed antimicrobials, accounting for 23% of prescriptions, while the second most prescribed were first-generation cephalosporins (21%). Conclusion: Overall, this study indicates that antimicrobial use was common, with 1 in 6 HD patients receiving antimicrobials during the 3-month study period. We believe this is the first Canadian study to describe prescribing patterns for both oral and IV antimicrobials in an outpatient HD population.