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 1000 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 1000 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 1000 DP and 0.1 AD per 1000 DP, respectively, whereas NM use increased at a rate of 0.1 AD per 1000 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.
Grant fund from Merck
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 .
P. R. Yarnold, None
T. S. Patel, Merck: Grant Investigator , Research grant .
L. Petty, None
G. Pais, None
K. Kaye, Zavante Therapeutics, Inc.: Scientific Advisor , Consulting fee .
M. H. Scheetz, Merck & Co., Inc.: Grant Investigator , Grant recipient . Bayer: Consultant , Consulting fee .