Impact of Antimicrobial Stewardship Program Intervention Acceptance on Hospital Length of Stay.

Background: Inappropriate antibiotic use is a major public health concern. Excessive exposure to antibiotics results in the proliferation of multidrug-resistant bacteria, increase in potentially avoidable adverse drug reactions, healthcare utilization, and cost. Currently, systematic reviews and controlled trials assessing the effects of antimicrobial stewardship programs (ASP) on hospital length of stay (LOS), mortality, and cost-savings are conflicting. Some studies reported a significant cost-savings driven by shorter hospital LOS while the others found no effect and, in some cases, prolonged LOS. Shortening the time to appropriate therapy and reducing unnecessary days of therapy have been shown to reduce hospital LOS. Objective: The purpose of this study was to evaluate the effects of prescriber acceptance to ASP interventions on hospital LOS. Methods: Between January 2018 and December 2019, 764 charts were retrospectively reviewed for patients who received antimicrobial treatment and in whom an ASP intervention was performed. Patients were allocated into 2 groups: those whose ASP interventions were accepted and those whose were rejected. Provider responses were then documented within 24 hours of being communicated. The primary outcome was hospital LOS. Secondary outcomes included 30-day readmission rates and inpatient antimicrobial duration of therapy (DOT). Results: There were 384 patients with an accepted ASP intervention and 380 with a denied intervention. Baseline characteristics were similar between both groups, except for a difference in the types of intervention performed (P < 0.001). The median hospital LOS for patients in the accepted intervention group was 6.5 days compared to 7 days in the rejected intervention group (P = 0.009). Antimicrobial DOT was also shorter in the accepted intervention group (5 vs 7 days; P < 0.001). There was no difference in 30-day readmission rates (P = 0.98). Conclusion: Prescriber acceptance to ASP interventions decreases hospital LOS and antimicrobial DOT without affecting 30-day readmission rates.