2025 Southeastern Residency Conference

Title: Evaluation of Appropriateness of Antibiotics Prescribed at ED Discharge for Urinary Tract Infections or Community Acquired Pneumonia in Medicare Patients 65+ 

Authors: Gabrielle Hopkins, Carlen Johnson, Nicole Gonzalez

Background: Antibiotics are some of the most prescribed medications in the Emergency Department. However, providers are often required to prescribe antibiotics prior to definitive culture results. Studies have shown that inappropriate prescribing may lead to patient harm, including adverse events, treatment failure, antimicrobial resistance, and hospital readmission. Community acquired pneumonia (CAP) and urinary tract infections (UTI) are among the top discharge diagnoses with the highest 30-day all-cause readmissions. This retrospective study aims to provide insight into ED discharge antibiotic prescribing patterns in Medicare patients 65+ for CAP or UTI at AdventHealth Central Florida Division (CFD) South campuses.

Method: The study was conducted as a retrospective chart review. Reports were populated through the electronic health record identifying Medicare patients 65 years at all AdventHealth CFD South campuses who were discharged from the ED with at least one antibiotic for CAP or UTI during the period of June 1, 2023 to June 30, 2024. Patients who were less than 65 years old, pregnant, incarcerated, discharged from the ED with CAP or UTI with no oral antibiotics, or had missing documentation were excluded from the study. De-identified patient data including demographics, antibiotic agent, antibiotic dose, duration of therapy, antibiotic appropriateness based on culture results, and markers of infection were collected for assessment. The primary outcome of this study was to evaluate the appropriateness of discharge ED antibiotic prescribing for CAP or UTI within the Medicare 65+ population. The antibiotic agent, dose, frequency, duration of therapy, and appropriateness of each agent based on culture results were assessed. The secondary outcome was inappropriate renal dosing associated with discharge antimicrobial treatment. Collected data was analyzed using descriptive statistics. 

Results: A total of 158 patients met the inclusion criteria and were included in data analysis. The median age was 78 years, the median weight was 72.5 kg, and the median height was 65 inches. The most common comorbidities included cardiac [131, (82%)], neurological [45,(28%)], and diabetes [38, (24%)]. Fifty-one patients diagnosed with UTI (34%) received ceftriaxone in the emergency department prior to discharge. Upon discharge, the most prevalent antimicrobial agent prescribed for UTI was cephalexin [65,(44%)] and most common organism identified was Escherichia coli [30, (18%)]. Cystitis was found to be the most common indication for antimicrobial therapy upon discharge [133 (84%)]. Nine (5.6%) patients were diagnosed with CAP. The most prevalent agent prescribed for CAP upon discharge was azithromycin [5, (55%)] and Mycoplasma pneumoniae [1 (11%] was identified to be the most common organism for CAP. The median duration of antimicrobial therapy was 7 days for UTI and 7 days for CAP. Further analysis revealed drug-bug mismatch in 22 (28%) patients, renal function mismatch in 87 (55%) patients and no microbiologic results in 40 (25%) patients.

Conclusion: Discharge antibiotic prescribing patterns varied amongst each CFD campus for Medicare 65+ patents who were discharged home on antimicrobial therapy for UTI or CAP. Twenty-eight percent (28%) of antibiotics prescribed at discharge did not appropriately treat the culture identified pathogens. Fifty-five percent (55%) of the antibiotics were dosed inappropriately based on renal function. This demonstrates an opportunity for pharmacist involvement to improve future patient care. Future directions include opportunities to improve rates of bug-drug match selection, education and resources for ED providers on proper antibiotic selection. Lastly, standardization of order sets for discharge antibiotics for patients discharged from all CFD EDs may improve appropriate discharge antibiotic prescribing. 

Self-Assessment Question: Which was the most common bacteria identified in patients with UTI? 
A. Staphylococcus aureus 
B. Escherichia coli 
C. Klebsiella pneumoniae 
D. Proteus mirabilis