348. Unnecessary Antimicrobial Use in Patients with Current or Recent Clostridium difficile Infection
Session: Poster Abstract Session: Clostridium difficile - Epidemiology, Diagnosis, Treatment, and Prevention
Friday, October 21, 2011
Room: Poster Hall B1
Background: Recurrence of Clostridium difficile infection (CDI) is common and difficult to treat. Antimicrobial use is a major risk factor for CDI, and antimicrobials are commonly used inappropriately. At our facility use of non-CDI antimicrobials is common both during and after new-onset CDI and is associated with recurrent disease; however, what fraction of this use is potentially unnecessary and therefore avoidable is unknown.

Methods: We retrospectively reviewed medical records at the Minneapolis Veterans Affairs Health Care System from 2004-2006. Pharmacy records and the computerized patient record system were used to identify: CDI cases, non-CDI antimicrobial use both during and up to 30 days after completion of CDI treatment, and patient characteristics. The number of non-CDI antimicrobial days and courses were calculated. Two Infectious Disease physician reviewers independently assessed the indication for non-CDI antimicrobials, using information available at the time the drug was ordered. An “unnecessary” designation was given if antimicrobial use was not indicated. Disagreements were resolved via discussion or evaluation by a third reviewer.

Results: Of 246 patients with new-onset CDI, 141 (57%) received non-CDI antimicrobials during and/or after CDI treatment, for a total of 2,140 antimicrobial days and 448 antimicrobial courses. One-third of the total antimicrobial days included unnecessary antimicrobials, and 71% of patients received at least one dose of an unnecessary antimicrobial. The two reviewers agreed (either with or without need for discussion) regarding the necessity of antimicrobials in >99% of the courses, with 25% of these courses requiring discussion to resolve disagreements.

Conclusion: At our institution, non-CDI antimicrobial use is common in patients with current or recent CDI and is associated with recurrent disease. A large proportion of this use is unnecessary and therefore potentially avoidable. Future investigation includes identifying the diagnoses, antimicrobials and patient characteristics most commonly associated with unnecessary antimicrobial use in this setting. These results may help limit non-CDI antimicrobial exposure in CDI patients, leading to fewer recurrences.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Megan K. Shaughnessy, MD1, William Amundson, BA2, Michael A. Kuskowski, PhD3, Douglas DeCarolis, PharmD3, Dimitri M. Drekonja, MD, MS3 and James Johnson, PharmD3, (1)Infectious Diseases, University of Minnesota, Minneapolis, MN, (2)University of Minnesota Medical School, Minneapolis, MN, (3)Minneapolis Veterans Affairs Medical Center, Minneapolis, MN


M. K. Shaughnessy, None

W. Amundson, None

M. A. Kuskowski, None

D. DeCarolis, None

D. M. Drekonja, None

J. Johnson, Merck: Grant Investigator, Research grant
Rochester Medical: Research Contractor, Research grant
Syntiron: Research Contractor, Research grant

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.