1871. Identifying Time Periods of High and Low Vancomycin Use

BACKGROUND: A national goal has been set to decrease inappropriate antibiotic use by 2020. To quantify decreases in use, consumption metrics and benchmarking strategies are implicit. However, while tracking and reporting antimicrobial use is widely recommended, these data do not address appropriateness. Accordingly, we developed a methodology to identify and report high and low vancomycin use periods which may represent inappropriate or unsafe antimicrobial use. METHODS: This is an observational, retrospective study of facility-wide vancomycin consumption data, aggregated, and examined on a hospital level from three academic medical centers: Northwestern Medicine (NM), Michigan Medicine (UM), and Henry Ford (HF) Hospital. Utilization was quantified as antimicrobial days (AD) per 1,000 days present (DP) on a monthly basis, recorded over 46 consecutive months (January 2014 through October 2017) for NM and HF, and 40 consecutive months (July 2014 through October 2017) for UM. Linear regression models and prediction intervals were generated to identify high-usage months. Use exceeding the upper bound of a prediction interval of 80 percent in a given month was used to define increased use, and the lower bound was used to define decreased use. RESULTS: Vancomycin use averaged 70.3 AD per 1,000 DP at NM, 89 at UM, and 153.8 at HF. Regression models indicated HF and UM consumption decreased at a monthly rate of 1.2 AD per 1,000 DP and 0.1 AD per 1,000 DP, respectively, whereas NM use increased at a rate of 0.1 AD per 1,000 DP over the study period. Overall, we identified n = 6, n = 5 and n = 6 vancomycin increased use months and n = 7, n = 6 and n = 5 decreased use months at NM, UM and HF, respectively. CONCLUSION: Our methodology identified a total of 17 potential instances of increased and 18 decreased use periods for vancomycin. Patient-specific and/or hospital-level factors may contribute to inappropriate vancomycin use and requires further study. The relationship between increased or decreased antibiotic use and appropriateness should be a focus in future efforts. Once the link between use and appropriateness is known, interventions can target specific use periods to maximize benefit of the intervention. DISCLOSURES: J. Liu, Merck: Grant fund from Merck, Research grant. S. Davis, Achaogen: Consultant and Scientific Advisor, Consulting fee. Allergan: Consultant and Scientific Advisor, Consulting fee. Melinta: Consultant and Scientific Advisor, Consulting fee. Nabriva: Consultant and Scientific Advisor, Consulting fee. Zavante: Consultant and Scientific Advisor, Consulting fee. T. S. Patel, Merck: Grant Investigator, Research grant. K. Kaye, Zavante Therapeutics, Inc.: Scientific Advisor, Consulting fee. M. H. Scheetz, Merck & Co., Inc.: Grant Investigator, Grant recipient. Bayer: Consultant, Consulting fee.