360. Routine surveillance versus independent assessment by an outcome adjudication committee in assessing patients for sternal surgical site infections after cardiac surgery
Session: Poster Abstract Session: HAI: Surgical Site Infections
Thursday, October 8, 2015
Room: Poster Hall
Posters
  • 360_SSI ID Week Poster - IJ_AK.pdf (73.3 kB)
  • Background: Independent data collection and assessment of possible cases by an outcome adjudication committee (OAC) is considered the gold standard for clinical trials where surgical site infections (SSI) are an outcome. It is unclear however, if routine infection control surveillance alone is sufficiently accurate to detect SSIs in clinical trials.

    Methods: We included all patients undergoing cardiac surgery by sternotomy at two Canadian high-volume centers (Hamilton, ON and Edmonton, AB) over a 4 month period. All patients were assessed through routine infection control surveillance using CDC/NHSN criteria, including chart review 90 days or later after surgery. Charts were also independently reviewed by a research assistant who, blinded to surveillance results, contacted patients 90 days after surgery, and presented patients flagged for a potential sternal SSI (s-SSI) to an OAC (three infectious disease physicians and one cardiac surgeon). The accuracy of surveillance compared with assessment by the OAC in identifying deep/organ space s-SSI using the CDC/NHSN definitions was assessed.

    Results: A total of 966 patients were included. There were 12 deep infections identified (1.2%) by surveillance and 11 (1.1%) identified by the OAC. There was disagreement in 7 cases (Kappa=69.2%). Compared with the OAC, sensitivity and specificity of routine surveillance was 72.7% (8/11; 95% confidence interval 39.03-93.98) and 99.6% (951/955; 95% confidence interval 98.93-99.89), respectively. The three cases with a deep/organ space s-SSI that were missed by surveillance, were not re-admitted to the study hospital and could therefore only be identified by a follow-up phone call by the research assistant. The four cases that were identified by surveillance but not by the OAC did not meet the CDC/NHSN definition, with 3/4(75%) being treated for presumed deep s-SSI by infectious disease physicians. 

    Conclusion: Routine surveillance alone did not prove to be sufficiently accurate in identifying deep/organ space s-SSIs. Adding a phone call at 90 days to routine surveillance however, plus an independent review by an OAC of cases identified as deep/organ space infections by routine surveillance, would improve the accuracy and may allow the use of surveillance data as a basis for cardiac surgery clinical trials.

    Dominik Mertz, MD, MSc1, Richard Whitlock, MD, PhD1, Stephanie Smith, MD, MSc2, Alex Carignan, MD, MSc3, Muhammad Rehan, MD1, Alicia Kokoszka, MSc4, Iqbal H Jaffer, MBBS1, Ali Alsagheir, MBBS, MSc1 and Mark Loeb, MD, MSc, FSHEA1, (1)McMaster University, Hamilton, ON, Canada, (2)Division of Infectious Diseases, University of Alberta, Edmonton, AB, Canada, (3)Microbiologie Et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada, (4)Population Health Research Institute, Hamilton, ON, Canada

    Disclosures:

    D. Mertz, None

    R. Whitlock, None

    S. Smith, None

    A. Carignan, None

    M. Rehan, None

    A. Kokoszka, None

    I. H. Jaffer, None

    A. Alsagheir, None

    M. Loeb, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.