Authors: Gresham Hindman; Hannah G Harpe; Haley L Meek; Steven Le
Background: Fluoroquinolones are one of the most frequently prescribed antibiotics, contributing to developing resistance to gram-negative organisms. At McLeod Health, our antibiograms show poor susceptibility of Escherichia coli and Pseudomonas aeruginosa to levofloxacin. With poor susceptibility, a growing area of concern is prolonged duration of fluoroquinolones. To address this, a practice advisory alert was created to encourage providers to consider the days of equivalent antibiotics received while inpatient when prescribing a fluoroquinolone at discharge. The purpose of this study was to assess the impact of this alert on duration of fluoroquinolone therapy prescribed at discharge from McLeod Health.
Methods: This was an institutional review board approved retrospective, multi-center, single-system, pre-post cohort study of adults discharged on levofloxacin or ciprofloxacin from any McLeod Health facility. Subjects were identified utilizing a report from the electronic health record. Two reports were generated between August 2024 and February 2025, one prior to activation of the alert and the second post activation. Data was collected via an electronic, password protected spreadsheet accessible only to the primary study investigators. Patients were excluded if they were pregnant, received a fluoroquinolone prescription for prophylactic/suppressive use, or diagnosed with a severe/complicated infection. Data collection endpoints included patient demographics, infection type, antimicrobial management, infectious disease consultation, prescriber credentials, and readmission within 30 days with a Clostridioides difficile diagnosis. The primary outcome measure was
incidence of inappropriate duration of fluoroquinolones prescribed at discharge according to current guidelines or infectious disease specialist recommendations, while accounting for inpatient antimicrobial use with equivalent coverage. The secondary outcome measure was the incidence of patients discharged on a fluoroquinolone and subsequently readmitted requiring treatment for Clostridioides difficile infection within 30 days of discharge. Derived from previous literature, a sample size of 540 patients was deemed necessary to obtain 80% power with an alpha of 0.05 to observe a 20% reduction of inappropriate durations prescribed at discharge.
Results: Two hundred participants were included in the study. Baseline characteristics were similar between both groups, however there was a difference in the infection type. The pre-practice advisory group had a higher incidence of urinary tract infections (38%) and intraabdominal infections (32%), whereas the post- practice advisory group had a higher incidence of pneumonias (40%). Of the 200 participants included, 151 (75.5%, 72 pre; 79 post) received inpatient antibiotic coverage that was considered equivalent to fluroquinolones. The most common agent used was ceftriaxone (pre 50% (36/72); post 56% (44/79)). The primary outcome, incidence of inappropriate duration of fluoroquinolones prescribed at discharge, occurred in 44% of patients in the pre-practice advisory group and 24% of patients in the post-practice advisory group, with an overall reduction of inappropriate prescribing by 20% (p=0.0028). Readmission in the pre- and post- groups were 12% and 6% respectively, however there was no incidence of Clostridioides difficile infections.
Conclusions: This retrospective cohort study demonstrated a statistically significant reduction in inappropriate durations of outpatient fluoroquinolone therapy through implementation of a practice advisory alert that notifies prescribers to consider the duration of antibiotic therapy received inpatient when prescribing fluoroquinolones at discharge. Our estimated reduction of inappropriate duration of therapy was 20% based upon a previous study, which we was met in this study. There was a statistically significant difference regarding the most prominent infection type between the groups, however this is attributed to the time of year data was collected from and respiratory infections being more common in the winter months. Overall, the practice advisory was effective and could potentially be expanded to other antibiotics in the future.
