707. Comparison of an Emergency Department-Specific Antibiogram to Hospital Antibiogram: Influence of Patient Risk Factors on Susceptibility
Session: Poster Abstract Session: Stewardship: Data and Program Planning
Thursday, October 5, 2017
Room: Poster Hall CD
  • 707 ED antibiogram ID Week.pdf (856.5 kB)
  • Background:

    Traditional antibiograms use local resistance patterns and susceptibility data to guide empiric antimicrobial therapy selection. However, antibiograms are rarely unit-specific and do not account for patient-specific risk factors. The objective was to develop an Emergency Department (ED)-specific antibiogram and evaluate the impact of risk factors on antimicrobial susceptibility.


    This retrospective, single-center descriptive study used culture and susceptibility data from January 1 to December 31, 2016 to create an ED-specific antibiogram for the most commonly isolated organisms. Susceptibilities were then compared to the hospital antibiogram. All ED isolates were further stratified by the following risk factors: age, disposition from ED, previous antimicrobial use and/or hospitalization within 30 days, and presenting location. Descriptive statistics, Pearson Chi-Square/Fisher’s Exact Tests, and logistic regression were performed. A two-tailed p-value of <0.05 was considered statistically significant.


    A total of 2158 isolates from the ED were included: Escherichia coli (EC) (n=1244), Klebsiella pneumoniae (KP) (n=232), Proteus mirabilis (PM) (n=131), Pseudomonas aeruginosa (PA) (n=103), Staphylococcus aureus (SA) (n=303), and Enterococcus faecalis (EF) (n=145). The majority of patients were <65 years old (n=1088) and presented from the community (n=1800) with no antimicrobial exposure (n=1628) nor hospitalization (n=1895) within 30 days. There were no statistically significant differences between the ED and hospital antibiogram (n=5739) for KP, PM, PA, SA, and EF. The hospital antibiogram overestimated EC resistance rates for cefazolin (20% vs 15.6%, p=0.049), ceftriaxone (9.6% vs 6.4%, p<0.033), and ciprofloxacin (23.7% vs 15.4%, p<0.006). There were significantly more risk factors present in patients discharged from the ED versus those admitted (p<0.0001). Healthcare facility residence had the greatest impact on susceptibility, especially EC (81.8% vs 34.9%, p<0.0001) and PM (75.3% vs 33%, p<0.0001) ciprofloxacin susceptibility.


    Development of an ED-specific antibiogram can aid physicians in prescribing appropriate empiric therapy when risk factors are included.

    Jessica Miller, Pharm.D., Amina George, Pharm.D. and Sarah M. Wieczorkiewicz, Pharm.D., BCPS AQ-ID, Pharmacy, Advocate Lutheran General Hospital, Park Ridge, IL


    J. Miller, None

    A. George, None

    S. M. Wieczorkiewicz, None

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