Clinical Burden of Antimicrobial Resistance Following Implementation of an Antimicrobial Stewardship Team Prospective Audit and Feedback Initiative at a Tertiary Care Centre: A Controlled Interrupted Time Series Over 14 Years

Background: Reducing antimicrobial resistance (AMR) is a major incentive for institutional antimicrobial stewardship programs (ASPs). However, there remains a paucity of high-quality data evaluating the impact of these programs on nosocomial AMR. The Sunnybrook Health Sciences Centre (SHSC) Bayview Campus is a shared site, home to a 627-bed acute care hospital and a 530-bed long-term-care facility (LTCF). A prospective audit-and-feedback (PAF) ASP was implemented in the acute care facility in October 2009. No specific intervention was initiated in LTCF, but there was potential for antimicrobial prescribing in the LTCF to be positively influenced by policy and practice at the adjoining acute care facility. This research evaluated the impact of the SHSC PAF-ASP on the burden of antibiotic-resistant organisms (ARO) and multidrug-resistant organisms (MDRO) and on inpatient antimicrobial use (AMU) in the 7 years following program implementation. Methods: Patient-level microbiologic and AMU data were retrospectively obtained over a 14-year study period (October 2002–September 2016). Interrupted time series Poisson regression models were used to detect PAF-ASP associated changes in the incidence and trend of hospital-acquired (HA-) ARO, HA-MDRO, and targeted (TGD) AMU and infer program impact. Changes in community-acquired (CA-) and long-term-care facility-acquired (LTCF-) ARO and MDRO were assessed for comparison. Results: PAF-ASP implementation was associated with improvements in HA-ARO incidence (9.3% reduction/post-intervention period, pPh.D.2019-11-19 00:00:0