Integrating Clinical Pharmacists into Emergency Department Culture Follow-Up: A Head-to-Head Comparison of Workflow Models

Background Microbiological results frequently finalize after patients are discharged from the emergency department (ED), necessitating efficient, accurate follow-up to optimize antimicrobial therapy and ensure appropriate patient care. Direct, head-to-head comparisons of culture follow-up models with and without clinical pharmacist involvement remain limited. Objective The purpose of this study is to compare time from culture result to initial review between a main ED with clinical pharmacist involvement and two external EDs without pharmacist involvement. Methods This single-center retrospective, observational study evaluated patients discharged from three EDs within one health system (August 2023 – February 2024) whose microbiology results finalized post-discharge. Clinical pharmacists reviewed cultures prior to advanced practice provider follow‑up within the main ED, while external EDs managed follow‑up without pharmacist involvement. The primary outcome was time from culture result to initial review. Secondary outcomes included callback intervention errors, time to first attempted patient contact, time to callback completion, and readmission rates. Data were analyzed using IBM SPSS (version 30.0). Categorical variables were compared with Pearson’s chi-square or Fisher’s exact test. Continuous variables were analyzed with Student’s t-test or Mann–Whitney U test, based on distribution. Results Among 300 patients (main ED, n=150; external EDs, n=150), the median time from culture result to initial review was shorter with pharmacist involvement: 3.1 hours [IQR 1.1-5.3] versus 8.8 hours [IQR 3.8-23.9] (p < 0.001). Median time from culture result to callblack completion was also shorter: 5.2 hours [1.7-27.3] versus 25.0 hours [5.8-57.6] (p < 0.001). Callback interventions were more often error-free in the pharmacist model (91.3% versus 77.3%, p = 0.001); the most common error at EDs without pharmacist involvement was antimicrobial initiation without indication (8.0%). No statistically significant differences were observed in time to first attempted patient contact, time to new prescription sent, prescription fill after contact, 30‑day hospitalization for the same condition, or readmission. Conclusion Integrating clinical pharmacists into ED culture follow‑up workflow was associated with faster initial review, callback completion, and fewer callback intervention errors, without detectable differences in downstream healthcare utilization. EDs should consider pharmacist‑integrated models to enhance the timeliness of post‑discharge culture management.