285. Consequences of Failure of Initial Antibiotic Therapy in Acute Bacterial Skin and Skin Structure Infections (ABSSSI) in US Hospitals, 2000-2009
Session: Poster Abstract Session: Antimicrobial Therapy: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Background: Initial antibiotic therapy in hospitalized patients with ABSSSI is typically empiric. Although usually successful, some patients fail to respond to such treatment. The clinical and economic consequences of failure of initial antibiotic therapy in ABSSSI have not been well described.

Methods: Using a US multi-hospital database, we identified all patients hospitalized for ABSSSI (e.g., abscess, cellulitis, surgical site infection) between 1/1/2000 and 6/30/2009 who had ≥1 positive isolates from skin, wound, and/or blood cultures ≤24 hours from initial clinical presentation, and who received parenteral antibiotic therapy for ≥48 hours (except in event of death), beginning within 24 hours of hospital admission. We designated all antibiotics received within 24 hours of admission as initial therapy, and we focused attention on patients receiving any of the 40 most commonly used regimens. Initial antibiotic failure was defined as: (1) receipt >24 hours from admission of an antibiotic not used in the first 24 hours, excluding agents of similar/narrower spectrum and those begun at hospital discharge; or (2) drainage, debridement, or amputation after 72 hours. We compared hospital length of stay (LOS), total billed charges, and mortality between patients who did versus did not fail initial therapy.  Analysis of covariance (ANCOVA) was used to assess the statistical significance of differences in LOS and charges; a chi-square test was used for mortality.

Results: Of 3485 patients who met all entry criteria, 779 (22.4%) experienced failure of initial antibiotic therapy. Patients who experienced failure of initial antibiotic therapy averaged 5.2 additional days in hospital (mean [SD], 9.1 [9.5] days vs 3.9 [3.0] days for those not experiencing failure) and $13,918 in additional hospital charges ($24,899 [$58,095] vs $10,981 [$17,114]) (p<0.01 for both comparisons). Case fatality was ~seven-fold higher in patients who failed initial therapy (1.0% vs 0.1%, respectively; p<0.01)

Conclusion: Patients hospitalized with ABSSSI who experience failure of initial antibiotic therapy have significantly worse clinical outcomes, longer lengths of stay, and higher costs of care.


Subject Category: A. Antimicrobial agents and Resistance

Ariel Berger, MPH1, Gerry Oster, Ph.D.1, John Edelsberg, MD, MPH1, Xing-Yue Huang, B. Pharm, Ph.D.2 and David Weber, MD, MPH, FIDSA3, (1)Policy Analysis Inc., Brookline, MA, (2)Forest Research Institute, Jersey City, NJ, (3)University of North Carolina, School of Medicine, Chapel Hill, NC

Disclosures:

A. Berger, Forest Research Institute: Research Contractor, Research grant
Pfizer: Research Contractor, Research support
Cubist: Research Contractor, Research grant

G. Oster, Forest Research Institute: Research Contractor, Research grant
Pfizer: Research Contractor, Research grant
Cubist: Research Contractor, Research grant

J. Edelsberg, Forest Research Institute: Research Contractor, Research grant and Research support
cubist: Research Contractor, Research grant
pfizer: Research Contractor, Research grant

X. Y. Huang, Forest Research Institute: Employee and Shareholder, Salary

D. Weber, Cubist: Collaborator, Consultant, Research Contractor and Speaker's Bureau, Consulting fee, Research grant and Speaker honorarium
Merck: Scientific Advisor and Speaker's Bureau, Consulting fee and Speaker honorarium
GSK: Scientific Advisor, Consulting fee and Speaker honorarium
Pfizer: Scientific Advisor and Speaker's Bureau, Consulting fee and Speaker honorarium
Ortho: Scientific Advisor and Speaker's Bureau, Consulting fee and Speaker honorarium
Sanofi: Scientific Advisor and Speaker's Bureau, Consulting fee and Speaker honorarium

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.