Antimicrobial Stewardship and Financial Outcomes Following Implementation of an Infectious Diseases Pharmacist Team...

Utilizing an antibiotic stewardship program (ASP), antibiotic use can be enhanced by pharmacists. However, no studies evaluate ASP implementation outcomes through incorporation of an infectious diseases (ID) pharmacist team at a community hospital. This evaluation aimed to: (1) determine the net return of the ID pharmacist team implementation through an antibiotic cost-avoidance counterfactual estimate; (2) evaluate usage trends of carbapenems, fluoroquinolones, and total antimicrobial use (AU) which encompassed all antibiotics, antivirals, and antifungals; (3) assess healthcare facility-onset Clostridioides difficile infection (HO-CDI) rates pre- and post-implementation of a 0.6 full-time equivalent (FTE) ID pharmacist team.

Single-site, retrospective, descriptive evaluation which consisted of adult patients (≥18 years) who received antibiotic, antiviral, or antifungal administrations or were diagnosed with HO-CDI during the study periods. The ID pharmacist team was implemented in September 2022. The pre-implementation period data for outcome (1) was collected from January 1, 2018, to December 31, 2020. The pre-implementation period data for outcomes (2) and (3) was collected from January 1, 2019, to December 31, 2020. The post-implementation period data for all outcomes was collected from January 1, 2023, to December 31, 2025. Patient-level data was not included. Descriptive statistics were used for data analysis.

The antibiotic cost-avoidance counterfactual estimate yielded an estimated net return of ~$323K for the implementation of the ID pharmacist team (~$639K avoided against ~$316K invested). Total AU decreased by 11.6% (-72.2 days of therapy (DOT)/1000 days present). Carbapenem use decreased by 75.6% (-27.6 DOT/1000 days present) and fluoroquinolone use decreased by 57.9% (-18.3 DOT/1000 days present). The incidence rate of HO-CDI per 1000 patient days decreased by 63% (incidence-rate ratio (IRR) 0.37; 95% CI [0.20-0.70]).

Findings display a positive net return for the implementation of the ID pharmacist team based on an antibiotic cost-avoidance counterfactual estimate. There was a decrease in total AU and utilization of high-risk Clostridioides difficile-causing antibiotics. A lower incidence rate of HO-CDI was observed. Results could be associated with antimicrobial stewardship (AMS) efforts correlated with implementation of the ID pharmacist team.