886. Predictors of Unfavorable Treatment Outcomes in Hospitalized Patients with Methicillin-Resistant Staphylococcus aureus (MRSA) Complicated Skin and Skin Structure Infections (cSSSI)
Session: Poster Abstract Session: Bone, Joint, and Soft Tissue Infection
Friday, October 19, 2012
Room: SDCC Poster Hall F-H
  • cMRSASSSIIDSA 2012PosterV09-28 dja.pdf (764.6 kB)
  • Background: cSSSI account for 10% of hospital admissions annually.  MRSA is the leading cause of cSSSI in the US.  Studies are lacking to aid in identifying hospitalized patients with cSSSI at risk for suboptimal initial treatment outcomes.  The objective of this study was to determine factors predictive of an unfavorable initial treatment outcome among hospitalized patients with MRSA cSSSI.

    Methods: This case-cohort study included adults diagnosed with MRSA cSSSI.  Collected data included demographics, treatment, infection, and outcomes.  We defined “unfavorable treatment outcome” as a composite of a need for additional surgery (beyond initial incision and/or debridement) of the infection site, intensive care unit admission, all-cause mortality, or need for re-hospitalization within 90 days.  We defined “appropriate initial therapy” as initiation of an antibiotic with in vitro activity against MRSA within 24 hours of obtaining a culture.  Multivariate regression analysis was performed to determine variables associated with an unfavorable treatment outcome.  Odds ratios (OR) were calculated for select variables; p-value <0.05 indicated statistical significance.

    Results: 675 of 1,884 identified patients were randomly selected for study inclusion.  Mean age of patients with unfavorable and favorable outcomes were 62.8 and 54.3 years, respectively.  53% of all patients were male. 255 (37.8%) patients experienced an unfavorable treatment outcome.  Age >65 years, diabetes, and Charlson score >3 were associated with an unfavorable initial treatment outcome (Table 1).  Initial appropriate therapy was not independently associated with an unfavorable treatment outcome.

    Table 1:  Variables associated with outcomes in hospitalized patients with MRSA cSSSI

    Independent Variable

    Unfavorable Outcome (n=255)

    Favorable Outcome (n=420)

    Odds Ratio;    p-value

    Age >65

    112 (44%)

    121 (29%)

    1.65; 0.004


    122 (48%) 

    137 (33%)

    1.56; 0.013

    Charlson >3

    109 (43%)

    118 (28%)

    1.48; 0.035

    Initial appropriate therapy

    120 (47%)

    202 (48%)

    1.10; 0.561

    Conclusion: Elderly patients with significant co-morbidities who are hospitalized for MRSA cSSSI were at higher risk for an unfavorable initial treatment outcome.  Results from this study have potential implications for restructuring current treatment protocols for MRSA cSSSI in hospitals.

    Deverick J. Anderson, MD, MPH1, Erich Cain, PharmD2 and Richard Drew, PharmD, MS, BCPS, FCCP1,3, (1)Duke University Medical Center, Durham, NC, (2)Campbell University/Kerr Drug, Fuquay-Varina, NC, (3)Campbell University School of Pharmacy, Durham, NC


    D. J. Anderson, None

    E. Cain, None

    R. Drew, None

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