Abstract
Background: Many infectious diseases are diagnosed in emergency departments (ED) and patients are prescribed antimicrobial therapy. Results from cultures typically take a few days to become finalized. Following up on these results is necessary when medication changes are indicated due to results that show bacteria are resistant to the prescribed antibiotics. Involving pharmacists in assessing the culture and sensitivity results, and making interventions when needed, is an innovative way to ensure that patients receive appropriate antimicrobial therapy based on the culture and sensitivity data. This study analyzed the impact of pharmacist involvement in the ED’s post-discharge positive culture review process on ED re-visits and hospitalizations. Methods: This single-center, pre- and post-implementation study examined the impact of pharmacist involvement in the post-ED visit culture review process on ED re-visits and hospitalizations. Positive microbiological results included documented growth from urine, skin and soft tissue, throat, blood, or stool cultures. Patients included in the study were of 18 years of age or older and had a positive culture result post ED-discharge. Patients were excluded from the study if they were admitted to the hospital or transferred to another facility. The primary outcomes included ED re-visits within 7 days and hospital readmissions within 30 days for the same condition. The secondary outcomes were percentage of pharmacist interventions accepted and types of pharmacist interventions implemented. Results: A total of 141 patients were included in the study, with 65 in the pre-implementation group and 76 in the post-implementation group. The primary outcome of ED re-visits within 7 days for the same condition occurred in 11 (17%) patients in the pre-implementation group and 5 (7%) patients in the post-implementation group (P = .0454). The primary outcome of hospitalizations within 30 days for the same condition occurred in 5 (8%) patients in the pre-implementation group and 1 (1%) patient in the post-implementation group (P = .0137). Seventeen (94%) out of the 18 pharmacist interventions were accepted and implemented. The intervention types implemented were to recommend to: change antibiotic (35%), not initiate antibiotic (24%), initiate antibiotic (24%), and continue antibiotic (18%). Conclusion: Pharmacist involvement in the ED post-discharge positive culture review process showed a decrease in ED re-visits and hospitalizations for the same condition.
Keywords: infectious diseases, clinical services, anti-infectives
Introduction
Pharmacists play a vital role in implementing principles of antimicrobial stewardship in medical settings. Many infectious diseases are diagnosed in the ED and patients are frequently prescribed antimicrobial therapy. Culture results typically take a few days to become finalized. Following up on these results is necessary to determine when therapy changes are indicated based on the culture and sensitivity results. Involving pharmacists in assessing these results and making interventions is an innovative way to improve prescribing of appropriate antimicrobial regimens and assure that patients receive appropriate antimicrobial therapy based on the culture and sensitivity data.1-5 This study analyzed the impact of pharmacist involvement in the post-ED visit positive culture review process on ED re-visits and hospitalizations.
Our institution involves pharmacists in both inpatient and outpatient settings. Two ED clinical pharmacists cover the ED from 3:00 pm to 1:00 am every day, 7 days per week. The ED clinical pharmacists are consulted by ED physicians for empiric antibiotic regimen recommendations prior to obtaining any culture results. However, pharmacists at our institution are not routinely involved with managing antimicrobial therapy for patients with a positive culture result post-discharge from the ED. Previous studies have assessed the benefits of involving pharmacists in the ED culture review process. The results demonstrated a reduced rate of treatment failure, less required interventions missed, reduced 30-day readmission rate, and faster time to contact patient when compared with previous processes that were driven by nurses and/or physicians. These studies involved ED pharmacists in the culture-review process by either managing it completely or contacting an advanced practice provider to finalize antibiotic changes.6-10 Therefore, we leveraged the antimicrobial stewardship knowledge of pharmacists and evaluated the impact of pharmacist involvement in post-discharge ED culture review at our institution.
Methods
Study Design
This was a pre-(February 2022 through May 2022) and post-(February 2023 through May 2023) implementation study, examining the impact of pharmacist involvement in the post-ED visit culture review process on patient ED re-visits and hospitalizations. Institutional review board approval was obtained for this study. Patients included in the study were of 18 years of age or older and had a positive culture result post ED-discharge. Positive microbiological results included documented growth from urine, skin and soft tissue, throat, blood, or stool cultures. Patients were excluded from the study if they were admitted to the hospital or transferred to another facility. The pharmacist was notified of patients with positive culture results post-ED visit by the ED secretary. The pharmacist then screened for the study’s inclusion and exclusion criteria. For patients meeting the inclusion criteria, the pharmacist reviewed the positive culture results and the discharge antimicrobial regimen to determine if an intervention was necessary. The pharmacist conducting the study was a pharmacy resident, who consulted ED clinical pharmacists, as well as other clinical pharmacy specialists, for recommendations when necessary.
Interventions in this study were defined as the recommendation to discontinue, change, or start an antimicrobial regimen based on cultures and sensitivity results. If an intervention was needed, the pharmacist provided a recommendation to the prescriber based on patient-specific factors and current treatment clinical guidelines. The prescriber then assessed the pharmacist’s recommendation and modified the antimicrobial regimen as deemed appropriate.
The primary outcomes were compared between the pre- and post-implementation periods. The primary outcomes were ED re-visit within 7 days or hospitalization within 30 days from the initial ED visit for the same condition. The secondary outcomes were the percentage of pharmacist interventions accepted and the types of pharmacist interventions implemented.
Outcome Measures
The primary outcomes were ED re-visit within 7 days or hospitalization within 30 days from the initial ED visit for the same condition. The secondary outcomes were the percentage of pharmacist interventions accepted and the types of pharmacist interventions implemented.
Statistical Analysis
Data analyses were performed using a chi-square test for the primary outcomes. A two-tailed alpha value of 5% and a confidence interval of 95% were used to determine the significance of the mean difference between the pre- and post-implementation periods with a power of 80%. A sample size of 90 patients was determined to be reasonable for this study. An electronic calculator was used to generate the P-value.
Results
A total of 141 patients were included in the study, with 65 in the pre-implementation group and 76 in the post-implementation group. The average age was 50 years in the pre-implementation group and 45 years in the post-implementation group. The majority of patients were female in both groups, representing 86 and 76% of total patients in the pre-implementation and post-implementation group, respectively. The most commonly reported race was White, with 48% in the pre-implementation group and 43% in the post-implementation group, followed by Black, with 31% in the pre-implementation group and 42% in the post-implementation group. Urine cultures accounted for the majority of the cultures, with 69% in the pre-implementation group and 82% in the post-implementation group. Cephalexin was prescribed most frequently at discharge, accounting for 42% of patients in each group (Table 1).
Table 1.
Baseline Characteristics.
| Characteristic | Pre-implementation (n = 65) | Post-implementation (n = 76) |
|---|---|---|
| Age, mean (years) | 50 | 45 |
| Sex, no. (%) | ||
| Female | 56 (86%) | 58 (76%) |
| Male | 8 (12%) | 18 (24%) |
| Unknown | 1 (2%) | 0 (0%) |
| Race, no. (%) | ||
| American Indian/Alaska Native | 1 (2%) | 1 (1%) |
| Asian | 1 (2%) | 3 (4%) |
| Black | 20 (31%) | 32 (42%) |
| Unknown/Other | 12 (18%) | 7 (9%) |
| White | 31 (48%) | 33 (43%) |
| Culture type, no. (%) | ||
| Blood | 6 (9%) | 2 (3%) |
| Genital | 5 (8%) | 0 (0%) |
| Throat | 0 (0%) | 3 (4%) |
| Urine | 45 (69%) | 62 (82%) |
| Wound | 9 (14%) | 9 (12%) |
| Antibiotic at discharge, no. (%) | ||
| Amoxicillin | 0 (0%) | 1 (1%) |
| Amoxicillin-clavulanate | 1 (2%) | 5 (7%) |
| Cefdinir | 4 (6%) | 2 (3%) |
| Cefpodoxime | 0 (0%) | 2 (3%) |
| Cefuroxime | 1 (2%) | 4 (5%) |
| Cephalexin | 27 (42%) | 32 (42%) |
| Ciprofloxacin | 2 (3%) | 2 (3%) |
| Clindamycin | 7 (11%) | 4 (5%) |
| Doxycycline | 2 (3%) | 2 (3%) |
| Levofloxacin | 2 (3%) | 1 (1%) |
| Nitrofurantoin | 1 (2%) | 1 (1%) |
| No antibiotic | 17 (26%) | 15 (20%) |
| Sulfamethoxazole-trimethoprim | 1 (2%) | 5 (7%) |
n = number of patientsp.
As shown in Table 2, ED re-visits within 7 days for the same condition occurred in 11 (17%) patients in the pre-implementation group and 5 (7%) patients in the post-implementation group (P = .0454). Hospitalizations within 30 days for the same condition occurred in 5 (8%) patients in the pre-implementation group and 1 (1%) patient in the post-implementation group (P = .0137).
Table 2.
ED Re-Visits Within 7 Days and Hospitalizations Within 30 days of the Initial ED Visit.
| Outcome | Pre-Implementation, n = 65 | Post-Implementation, n = 76 | P value (chi-square test) |
|---|---|---|---|
| ED re-visit for the same condition within 7 days of the initial ED visit | 11 (17%) | 5 (7%) | 0.0454 |
| Hospitalization for the same condition within 30 days of the initial ED visit | 5 (8%) | 1 (1%) | 0.0137 |
ED = emergency department; n = number of patients.
Seventeen (94%) out of 18 pharmacist interventions were accepted and implemented. As shown in Figure 1, recommend to change antibiotic (35% of total interventions) was the most common intervention implemented. This was followed by recommend to initiate antibiotic (24%), recommend to not initiate antibiotic (24%), and recommend to continue antibiotic (18%).
Figure 1.
Intervention types implemented.
Total number of interventions implemented = 17.
Discussion
Patients in the post-implementation group had less ED re-visits within 7 days and less hospitalizations within 30 days of the initial ED visit compared to the pre-implementation group. Similarly, patients in the post-implementation group had less hospitalizations for the same condition within 30 days of the initial ED visit compared to the pre-implementation group. The majority of pharmacist interventions were accepted and implemented, with the most common one being the recommendation to change the antibiotic. Urine cultures accounted for the majority of the culture types, and cephalexin was the most commonly prescribed antibiotic at discharge at baseline in both groups.
The results from our study are similar to those from other studies involving pharmacists in the ED post-discharge positive culture review process. Our study adds to the existing literature and supports expanding the role of the pharmacist in the post-discharge positive culture review process. Of note, our study was not designed to capture the time from positive culture result availability/review to patient notification and we did not follow up with patients to confirm if they obtained the appropriate antimicrobial therapy. Future studies could investigate these aspects to further characterize the impact of pharmacist involvement in the post-discharge positive culture review.
Limitations
Limitations to this study include reliance on complete and accurate documentation for patient assessment in the electronic health record (EHR) when determining recommendations. Additionally, not all ED visits or hospitalizations may be captured in the databases used to assess the primary outcomes.
Conclusion
Pharmacist involvement in the ED post-discharge positive culture review process showed a statistically significant decrease in ED re-visits and hospitalizations for the same condition. This study demonstrates the positive impact of pharmacist involvement on patient outcomes.
Directions for the future include continuing to involve pharmacists in the ED post-discharge positive culture review process and expanding pharmacist antimicrobial stewardship interventions in the outpatient setting. Expanding ED clinical pharmacist coverage would be beneficial in further leveraging their expertise in antimicrobial stewardship and allowing them to further embed themselves in the ED post-discharge culture review process. Lastly, an institutional protocol could be developed for ED clinical pharmacists to independently make interventions and conduct follow-ups with patients, consulting with physicians and prescribers only when necessary.
Acknowledgments
The author(s) of this study would like to thank the Holy Cross Hospital staff and patients who participated in this study for facilitating the conduction of this study.
Footnotes
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.
ORCID iD: Andrea Richardson 
https://orcid.org/0009-0005-5491-5796
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