# Antibiotic use and financial impact of a comprehensive beta-lactam allergy management program

## TL;DR

A beta-lactam allergy management program reduced unnecessary antibiotic use and saved costs by confirming many patients were not truly allergic.

## Contribution

Demonstrates large-scale cost and antibiotic use savings from penicillin skin testing in inpatients.

## Key findings

- 98% of patients tested negative for beta-lactam allergies.
- The program avoided 8.8 days of non-beta-lactam therapy per patient.
- Total estimated cost savings reached $206,500 over 5 years.

## Abstract

A multidisciplinary beta-lactam allergy management program was implemented at our community medical center to facilitate allergy documentation, conduct penicillin skin testing (PST), and decrease non-beta-lactam (NBL) use. This study measures PST-associated antibiotic use and financial outcomes.

Cohort study.

Non-teaching, urban, community medical center within a multi-hospital health system.

Adult inpatients who underwent PST and received antibiotic therapy during a 5-year period at our facility.

Demographics, allergies, laboratory results, PST outcome, and antimicrobial regimens were assessed. Actual NBL days of therapy (DOT) were collected from the electronic medical record. NBL DOT that patients would have received without PST were modeled by forecasting the original regimen to end of inpatient treatment. Difference between actual and forecasted DOT was deemed DOT avoided (DOT-A) for each consecutively enrolled patient. The financial analysis evaluated cumulative NBL cost avoided. PST outcomes and average time from antibiotic initiation to PST were assessed.

The study included 600 patients who underwent PST an average of 3.7 days into treatment. The most common indication was acute bacterial skin and skin structure infections (23.9%). PST results were negative in 98% of patients. NBL DOT-A was 944.8/1000DT (8.8 DOT-A per intervention) accounting for an estimated cost savings of $206,500 ($344.10 per intervention), driven primarily by aztreonam avoidance.

This study highlights significant avoidance of NBL DOT in one of the largest identified cohort of inpatients undergoing PST. Associated cost avoidance contributes to the sustainability and longevity of the allergy management program.