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Denominator Matters in Estimating Antimicrobial Use: A Comparison of Days Present and Patient Days

  • Rebekah W. Moehring (a1), Elizabeth S. Dodds Ashley (a1), Xinru Ren (a2), Yuliya Lokhnygina (a2), Arthur W. Baker (a1), Travis M. Jones (a1), Sarah S. Lewis (a1), Daniel J. Sexton (a1), Deverick J. Anderson (a1) and the Centers for Disease Control and Prevention Epicenters Program...


Patient days and days present were compared to directly measured person time to quantify how choice of different denominator metrics may affect antimicrobial use rates. Overall, days present were approximately one-third higher than patient days. This difference varied among hospitals and units and was influenced by short length of stay.

Infect Control Hosp Epidemiol 2018;39:612–615


Corresponding author

Address correspondence to Rebekah W. Moehring, MD, MPH, Duke University Medical Center, 315 Trent Drive, Durham, NC, 27705 (


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Moehring et al. supplementary material
Moehring et al. supplementary material 1

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