# P-926. Defaults by Design: Impact of Default Antimicrobial Order Durations on Prescribing Patterns in the Emergency Department

## TL;DR

Changing default antibiotic prescription lengths in emergency departments reduced antibiotic use without increasing readmissions.

## Contribution

A low-resource EHR update reduced antimicrobial days supply in EDs without affecting readmission rates.

## Key findings

- Average antimicrobial days supply decreased from 7.9 to 6.9 days post-intervention.
- Approximately 36,000 antibiotic days were saved over one year.
- No significant difference in 30-day ED readmission rates before and after the intervention.

## Abstract

Many outpatient infections can be effectively treated with shorter (5-day) rather than longer (7-14 day) antimicrobial courses. While emergency department (ED)-focused antimicrobial stewardship (AMS) efforts are expanding, electronic health record (EHR) optimizations to impact prescribing of antimicrobial durations have not been robustly defined.

This quality improvement initiative occurred at five EDs within a community health system. An update was made in the EHR to change the default dispense quantity of all oral antimicrobials at ED discharge to a 5-day supply. Adult patients receiving ≥1 oral antimicrobial at ED discharge were included. Pre- (2022) and post-intervention (2023) data were compared. The primary endpoint was the average antimicrobial days supply prescribed. Other endpoints included patient demographic and encounter data, primary diagnoses, antimicrobials prescribed, and 30-day ED readmission.

There were 33,226 ED encounters (39,253 antimicrobial prescriptions) pre-intervention vs. 37,545 post-intervention (44,824 antimicrobial prescriptions). Mean age was 49 years; 59% of patients were female. Top primary diagnoses were respiratory viruses, urinary tract infections, skin and soft tissue infections, intra-abdominal infections, and dental infections. Cephalosporins (34% vs. 36%) and penicillins (17% vs. 19%) were the most common antimicrobial classes prescribed in the pre- and post- groups, respectively. Average oral antibiotic days supply was reduced by 1 day pre-post intervention (7.9 days vs. 6.9 days; p < 0.001), resulting in an estimated 36,000 days of antibiotics saved over the 1-year timeframe. There were no differences in 30-day ED readmission (17.6% vs. 17.8%, p=0.37).

This high impact, low resource EHR update to default dispense quantities for ED-discharge oral antimicrobial prescriptions was associated with a significant reduction in antimicrobial days’ supply with no difference in 30-day ED readmission. Similar interventions could be considered to help support appropriate antibiotic prescribing in community health system ED environments with limited AMS resources.

All Authors: No reported disclosures

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Source: https://tomesphere.com/paper/PMC12791244