309. The Misidentification of Preventable Infections: MRSA LabID events
Session: Poster Abstract Session: HAI: Epidemiology
Thursday, October 8, 2015
Room: Poster Hall
  • IDWeek MRSA poster 2015 _final.pdf (438.4 kB)
  • Background:

    Beginning January 1, 2013, acute care facilities were required to submit methicillin-resistant Staphylococcus aureus (MRSA) laboratory-identified events (LabID) to the National Healthcare Safety Network (NHSN) for Centers for Medicare and Medicaid Services (CMS) Hospital Inpatient Quality Reporting. Our institution's MRSA LabID standardized infection ratio (SIR) of 1.497 was double the national median (0.785). We undertook this review to determine where to focus infection prevention (IP) efforts.


    Data submitted from September 2013-February 2015 were evaluated. Medical records were reviewed to determine if the positive blood cultures were: central line-associated bloodstream infection (CLABSI), BSI not central line associated, secondary to another infection, present on admission (POA) or duplicate. Secondary infections were defined per NHSN criteria. If the positive blood culture was collected in the ED prior to admission, it was considered POA (consistent with the 2014 definition); duplicates included patients who had transferred to another inpatient unit and had subsequent positive blood cultures.


    Thirty five MRSA LabID events were reported in eighteen months (Table 1). Of these, only 15 (43%) were primary BSIs, twelve (34%) were secondary BSI, 4 (11%) POA and 4 (11%) duplicate (Figure 1).


    MRSA LabID event is defined as a MRSA blood culture collected ≥ day 3 of admission in any location, excluding prior positives in the same location within 14 days. No other positive MRSA cultures are reported. Unlike other NHSN-derived CMS metrics, this is a proxy report based solely on admission date, patient movement within the facility, and culture date(s).  Over half of our events were not primary BSIs; 22% were POA or duplicate which are not preventable. Further, secondary BSIs may or may not be preventable. Our findings highlight limitations of this metric, as the data inflate SIR by counting duplicates, allowing for consecutive cultures in different locations, and fail to recognize secondary infections; thus, SIR is not reflective of overall hospital quality performance. This metric should be further evaluated before it is used to reflect quality and safe care.

    Table 1:

    Event Type




    Primary BSI


    Secondary BSI








    Figure 1:


    Christina Silkaitis, MT (ASCP), CIC1, Larysa Fedoriw, MPH, CIC2, Maureen Bolon, MD, MS1, Cynthia Barnard, MBA, MSJS, CPHQ3 and Teresa Zembower, MD, MPH, FIDSA4, (1)Healthcare Epidemiology and Infection Prevention, Northwestern University, Chicago, IL, (2)Healthcare Epidemiology and Infection Prevention, Northwestern Memorial Hospital, Chicago, IL, (3)Quality, Northwestern Memorial Healthcare, Chicago, IL, (4)Northwestern University Feinberg School of Medicine, Chicago, IL


    C. Silkaitis, None

    L. Fedoriw, None

    M. Bolon, None

    C. Barnard, None

    T. Zembower, None

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