Assessing the Impact of a Unit-Based Clinical Pharmacist on Antimicrobial Use in a Level I Trauma Center – A Pilot Study



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Background Often, Pharmacists have an opportunity to improve quality, enhance patient safety, and work side by side with key members of the primary patient care team. Studies show that optimum medication use is demonstrated in only 4-21% of patients. Greater pharmacist involvement has been shown to lead to fewer re-hospitalizations, lower healthcare costs, better adherence to evidence-based consensus guidelines, and better outcomes. Harris Health System launched its antimicrobial stewardship program, through coordinated efforts of the infectious disease teams, internal medicine, critical care medicine, surgery, hematology/oncology, emergency medicine, microbiology/pathology, nursing, pharmacy, and infection control/epidemiology. It is the goal of the antimicrobial stewardship program to optimize the utilization of antimicrobial agents in order to realize improved patient outcomes, a positive effect on antimicrobial resistance, and an economic benefit. While there is an antimicrobial stewardship program in place, it is a consult-based service and the opportunity remains to reach additional patients. The pilot program of unit-based pharmacists would ensure a clinical pharmacist building a closer relationship with the antimicrobial stewardship team to improve patient outcomes such as using the right agent, at the correct dose, for the appropriate duration in order to cure or prevent infection, while minimizing toxicity and emergence of resistance. The current state at the level 1 trauma center at Ben Taub Hospital, involves all pharmacists within the central pharmacy practicing all duties centralized in the inpatient pharmacy and primarily focusing on distributive services. Bringing the pharmacist closer to the bedsides will enable them to practice at the top of their licenses with an even distribution of clinical and distributive services. Beginning on September 27th, 2021, decentralized pharmacists will be piloted at Ben Taub Hospital on three internal medicine units where they will have the opportunity to make quality interventions, work closely with the primary patient care team and place patient care as a priority on the journey of becoming a high-reliability organization. While bringing pharmacists to the unit will impact many patient outcomes, this study will focus on antimicrobial use as the increasing need for antimicrobial stewardship is at the forefront of clinical pharmacy practice. This study is a prospective, single-center study. Data will be collected for a 6-week period pre-and post- implementation (pre: July - August 2021 and post: September - December 2021). The primary outcome of the impact of a Unit-Based Pharmacist will be on reduction in cost by the change of antibiotics from IV to PO within 3 days and a secondary endpoint of days of therapy by a de-escalation of antimicrobial use within 48 hours of lab results.

Results A total of 240 patients receiving antibiotics were randomly selected during the study period. The 6-week period pre-implementation was from July 19th, 2021, to August 30th, 2021, while the 6-week pilot implementation period was from September 27th, 2021, to November 8th, 2021. A total of 10 patients per week during the study period were evaluated for both primary and secondary endpoints (120 patients for each endpoint), from those 240 patients, 22 patients did not meet the criteria. (Figure 1) The study results indicated the modification from IV to PO antimicrobial use to be statistically significant (p-value = 2.354e-06, =0.05) with a proportional increase in IV to PO from 3% to 33%, with an odds ratio of 18.2. (Figure 2) IV to PO cost impact was beneficial, resulting in an estimate of -25.604 which states for every IV to PO switch that occurred an average of $25 dollars was saved which was shown to be statistically significant (p-value = 0.039, =0.05). (Figure 3) Logistic regression analysis was used to show improvement heading in the correct direction. The proportion of de-escalation of IV vancomycin resulted in 57.4% to 66.7% improvement from pre to post-implementation endpoint (p-value = 0.2012, =0.05) which was not statistically significant although heading in the direction of improvement. (Figure 4)

Conclusion The use of unit-based pharmacists shows an improvement in providing better patient care and cost savings to health systems for converting from intravenous to oral medication therapy. Despite sample-size limitations, this study demonstrated correlates and missed opportunities to convert antimicrobials from IV to PO, which warrants providers' attention. This study showed intravenous to oral therapy switch to increase by 38% and a cost difference of $25 for every IV to PO switch that occurred, which is not all-inclusive of cost to the hospital for a length of stay of patients. De-escalation of empiric antimicrobial therapy is increasingly recognized as an important principle of antibiotic stewardship. While it may not be feasible or appropriate in every instance, this study adds to the literature as potential benchmarks for antibiotic de-escalation are being considered. Further studies will demonstrate the feasibility and benefits of a decentralized pharmacist.



Unit-based, Antimicrobial