Vol. 2, Issue 2, Part A (2025)

Background: Broad-spectrum antimicrobial overuse in tertiary hospitals drives antimicrobial resistance and increases Clostridioides difficile infection (CDI). Evidence supports pharmacist-led stewardship, but real-world, risk-adjusted impacts tied to the Standardized Antimicrobial Administration Ratio (SAAR) remain important to quantify.
Objective: To evaluate whether a pharmacist-led stewardship bundle reduces broad-spectrum use and hospital-onset CDI without compromising safety.
Design and Setting: Quasi-experimental interrupted time-series study in a 1,000-bed tertiary-care academic hospital, comparing 12 pre-intervention months with 12 post-implementation months.
Participants: All adult inpatients across medical-surgical wards and mixed ICUs.
Intervention: A pharmacist-led bundle comprising daily prospective audit-and-feedback prioritized to “Watch/Reserve” agents, indication-linked preauthorization for fluoroquinolones and antipseudomonal β-lactams, mandatory 48-72 h “time-outs,” IV-to-PO conversion criteria, and syndrome-specific order sets with transparent unit-level dashboards.
Main Outcomes and Measures: Primary broad-spectrum SAAR (adult inpatient, hospital-onset indications) and broad-spectrum days of therapy (DOT) per 1,000 patient-days. Secondary—hospital-onset CDI incidence per 10,000 patient-days, time-to-effective therapy, time-to-narrowing, IV-to-PO conversion, and safety (in-hospital mortality, 30-day readmission).
Results: Mean SAAR declined from 1.274 pre-intervention to 1.015 post-intervention (relative change −20.3%). [REVISION: values aligned to Table 1] Broad-spectrum DOT fell from 620.6 to 499.7 per 1,000 patient-days (−19.5%). [REVISION: values aligned to Table 1] Hospital-onset CDI decreased with an incidence rate ratio of 0.65 (95% CI, 0.55-0.76). [REVISION: values aligned to Table 1] Process fidelity improved during the intervention: pharmacist audit-and-feedback encounters increased (>520/month by study end), recommendation acceptance rose to ≈85%, IV-to-PO conversion reached ≈56%, and 48-72 h time-out completion approached ≈88%. No increase occurred in in-hospital mortality or 30-day readmission.
Conclusions: A pharmacist-led, SAAR-guided stewardship bundle produced rapid and durable reductions in broad-spectrum antibiotic exposure and hospital-onset CDI in a complex tertiary setting without safety trade-offs. Embedding 48-72 h reassessment, targeted preauthorization, dialogue-based audit-and-feedback, and standardized order sets coupled with transparent feedback dashboards—offers a scalable pathway for hospitals seeking concurrent reductions in antimicrobial use and CDI burden.