2025 Southeastern Residency Conference

Title: Evaluation of Outpatient Parenteral Antimicrobial Therapy and Antimicrobial Stewardship Program Practices at a Veterans Affairs Medical Center


Authors: Alley Minton, Bailey Guest, Cassidy Prewitt, Galina Wang


Objective: To evaluate the efficacy of OPAT.


Self Assessment Question:  Which of the following is an example of a patient who would likely qualify for OPAT through SVAHCS?


Background: Outpatient parenteral antimicrobial therapy (OPAT) refers to the delivery of parenteral antimicrobial treatment in at least two doses on different days without requiring hospitalization. Many individuals are eligible for OPAT with the intent to effectively treat the ongoing infection with medical oversight, reduce or offset hospitalization, decrease healthcare costs and improve quality of life. Antimicrobial stewardship plays a crucial role in promoting the safe and appropriate use of antimicrobials to combat the rise of antibiotic resistance. Hospitals that have implemented antimicrobial stewardship programs (ASP) have reported significant reductions in unnecessary antibiotic prescriptions and improved patient outcomes. At the Salisbury Veterans Affairs Health Care System (SVAHCS), the OPAT program is overseen by a full-time Infectious Diseases physician assistant, with essential support from the Infectious Diseases (ID) clinical pharmacist practitioner (CPP), an ID/Acute Care CPP, and rotating ID physician oversight. This OPAT program is unique due to majority of requests for OPAT originate from surrounding non-VA healthcare facilities. In 2023, OPAT maintained a consistent enrollment of 149 patients, compared to 158 in 2022 and 122 in 2021, with various treatment regimens and durations.


Methods: This quality improvement project will be conducted as a retrospective cohort study. The main objective is to assess the efficacy of OPAT. Primary outcomes will focus on readmission rates to a hospital while receiving OPAT due to complications, adverse events, treatment failure or for reasons unrelated to infection or OPAT regimen. Secondary objectives include evaluating safety, antimicrobial stewardship interventions, the reduction of hospital bed days of care (BDOC) and intravenous (IV) line days avoided associated with OPAT. Secondary outcomes will include rate of OPAT completion, potential cost savings, 30-day readmissions post-OPAT (including reasons), and 30-day mortality following OPAT.


Results: 567 patient were extracted from data from January 2022 to December 2024. 398 patients were included, 122 patients did not meet inclusion criteria, and 47 were excluded by the exclusion criteria. 53 patients were readmitted during OPAT therapy, accounting for 13% of the total amount of patients included. The primary reason for readmission was due to concomitant disease which included 27 patients and 51% of the patients readmitted. Antibiotic failure was the second most common at 15 patients (28%), followed by adverse effects at 11 patients (21%). The readmission rate 30 days after OPAT completion only included 9 patients, 2% of the total patient population included. Comparable to the readmission rate, the primary reason for readmission was concomitant disease at 6 patients (66%) followed by 2 patients for antibiotic failure and 1 patient with C. difficile infection. The total OPAT completion rate was 97% with 386 patients. Mortality 30 days after OPAT was 1% with 5 patients. The average number of bed days of care avoided were 3,337 per year. The average number of IV-line days avoided were 134 per year. Over the 3-year span, there were 4,575 documented interventions. Aside from a high number of evaluations and follow-up reviews, laboratory monitoring, nonformulary requests, drug information, duration change, and medication change were the top 5 ASP interventions.


Conclusion: OPAT at the SVAHCS is an efficacious alternative to prolonged hospitalization to complete antimicrobial treatment. OPAT data that was collected over the past 3 years has shown improvement since OPAT was last evaluated in 2017 at SVAHCS. Readmission rates are comparable to current literature with approximately half being unrelated to infection. Almost all patients who initiated OPAT with the SVAHCS completed therapy successfully with minimal complications and low overall 30-day mortality. SVAHCS ASP is integrally involved in OPAT routinely recommending and now documenting interventions and potential cost savings through TheraDoc.

Contact Information: alley.minton@va.gov