Trends in Long Duration Antibiotic Prescribing Following Focused Outpatient Antimicrobial Stewardship Efforts Across a Large Healthcare Enterprise

Abstract Background Outpatient antibiotic stewardship programs (ASP) are recommended by the CDC and Joint Commission. We analyzed the impact of annual, focused syndrome-specific ASP interventions on trends in long-duration antibiotic prescribing (LDAP). Methods This was a retrospective, observational, multicenter cohort study from November 2020 through June 2025. All ambulatory encounters generating systemic antibiotic prescriptions within the healthcare enterprise were screened. Hospitalizations, emergency department visits, and infectious diseases encounters were excluded. Encounters generating ≥1 systemic antibiotic with 7 days duration were categorized as long-duration. Targeted departments (primary and urgent care) received direct intervention (e.g., education, peer-comparison reporting, data tracking). LDAP was modeled over time by month and compared by diagnosis group (ASP-priority diagnoses vs non-priority) and provider specialty department (ASP-targeted vs non-targeted) using linear regression models. Results Of 642,579 encounters included, 42.2% were long duration. LDAP in ASP-targeted departments dropped from 46.8% to 34.8% (difference -12 percentage points pp), whereas non-targeted departments dropped from 45.5% to 39.1% (difference -6.4pp). The estimated annual LDAP decrease was 3.4 pp in targeted vs 2.4 pp in non-targeted departments (difference 1.0 pp, P=0.009). Within targeted departments, significant LDAP decreases were seen both in priority and non-priority diagnoses, whereas non-targeted departments showed no change in LDAP in priority diagnoses. In a sensitivity analysis of non-priority diagnoses, ASP-targeted departments had a larger estimated annual decrease vs non-targeted (difference 1.4 pp, P0.001). Conclusions Annual syndrome-specific ASP interventions correlated with improvements in LDAP, including outside of priority syndromes in targeted departments. LDAP is a viable metric for evaluating ambulatory ASPs.