Eight Years of Antimicrobial Stewardship Program (ASP) at a Large Academic Medical Center: Antibiotic Utilization, Hospital-onset Clostridium difficile infection (HO-CDI) and Resistance Trends

Abstract

BackgroundAntibiotic (ABX) use and outcome measures (rate of HO-CDI, local antimicrobial resistance) are recommended ASP metrics. These metrics can be used for internal benchmarking to assess ASP performance within an institution over time.MethodsAn adult ASP at our 750-bed academic medical center was implemented in 2008. ASP interventions include prospective audit and feedback, prior authorization with fluoroquinolone (FLQ) restriction as an ASP target and implementation of facility-specific guidelines for common infections. Newer ASP initiatives were Cepheid/Xpert for blood cultures with Gram-positive cocci in pairs and clusters with daily real-time ASP interventions (11/2014), oral vancomycin secondary prophylaxis for patients with prior CDI (4/2014) and optimization of β-lactam (BL) dosing (piperacillin-tazobactam [PTZ] extended infusion hospital-wide 4/2013; cefepime [CEF] 4/2015 and meropenem 7/2015 protocols). ABX use is measured in days of therapy per 1000 patient-days (DOT/1000 PD) and length of therapy/admission when ABX were administered (LOT/ADM). NHSN definition is used for HO-CDI. For resistance trends the first unique isolate/patient/year regardless of source or susceptibility profile was included. Statistical analysis of trends during 8-years period 2009–2016 was performed by Poisson (SAS).ResultsMajor shifts in ABX use include decrease in FLQ use (-17%, P < 0.01) with compensatory increase in ceftriaxone (CTX, +12%, P < 0.01), antipseudomonal BL (+3%, P < 0.01) and no change in carbapenem (+0.6%, P=0.5) as well as an increase in nafcillin and oxacillin (+7%, P < 0.01) use. There was a decrease in aggregate LOT/ADM (-4%, P < 0.01) with no change in DOT/1000 PD. We observed a decrease in HO-CDI rate (-17%, P < 0.01). Major resistance trends include reduction in Enterobacteriaceae spp. and Pseudomonas aeruginosa isolates nonsusceptible (NS) to FLQ (-4%, P < 0.01; -10%, P < 0.01, respectively) with increase in Enterobacteriaceae spp. NS to ceftriaxone, (+3%, P < 0.01). A decrease in P. aeruginosa NS to PTZ (-11%, P < 0.01) and no change for CEF was reported. There was no difference in Enterobacteriaceae spp. NS to PTZ or CEF.ConclusionOverall, reported trends aligned with ASP initiatives. Increased CTX NS is of concern and warrants an ASP-led strategy to decrease CTX use.Disclosures All authors: No reported disclosures.