2066. The effect of a piperacillin/tazobactam shortage on antimicrobial prescribing and hospital-onset Clostridium difficile infection rates in 88 U.S. medical centers
Session: Poster Abstract Session: Clostridium difficile: Epidemiology
Saturday, October 29, 2016
Room: Poster Hall
Background: The adverse effects of anti-infective shortages have not been well described. Piperacillin/tazobactam (P/T) is considered to have a low-risk for C. difficile infection (CDI) relative to other agents like 3rd/4thgeneration cephalosporins. Objective: to identify any association between changes in antibiotic use during a national P/T shortage and hospital-onset CDI (HO-CDI) rates in U.S hospitals.

Methods: We analyzed electronically captured microbiology and antibiotic usage data from U.S. hospitals for 2 quarters before and 2 quarters after the P/T shortage that began in 12/2014. Antibiotics classes considered to have a high-risk for CDI were defined a priori. The primary endpoint was HO-CDI defined as a positive C. difficileresult (toxin or molecular assay) obtained >3 calendar days after hospital admission in patients without a positive assay in the previous 8 weeks. We fit a Poisson model to estimate the risk of HO-CDI associated with the varying levels of P/T shortage and resulting changes in high-risk antibiotic usage.

Results: 88 hospitals experienced a P/T shortage; 39 experienced a mild shortage (<33% decrease in P/T) and 49 experiencing a moderate/severe shortage defined as a ≥ 33% decrease in P/T (mean change in DOT/1000 days at risk pre and post shortage was 80.8 and 23.6, respectively; P<0.001). Of the 88 hospitals with P/T shortage, 72 had a resulting increased use of high-risk antibiotics. The pre-post differences in DOT/1000 DAR for high-risk antibiotics in hospitals with no, mild, moderate, or severe P/T shortages were: -17.2 (P=0.29), 15.6 (P<0.05), 53.5 (P<0.05), 98.1 (P<0.05) respectively. The adjusted relative risk (ARR) of HO-CDI for hospitals with P/T shortage was 1.03 (95% CI: 0.85, 1.26; P=0.73). The ARR of HO-CDI for increasing high-risk antibiotics use was 1.30 (95% CI: 1.03, 1.64; P<0.05).

Conclusion: Hospitals impacted by a recent national shortage of P/T showed increased use of agents with high-risk for CDI. The shift toward increased high-risk antibiotic usage was associated with increased rates of HO-CDI. This study suggests a national antibiotic shortage may be associated with patient harm.

Alan E. Gross, PharmD, BCPS-AQ ID1,2, Vikas Gupta, Pharm.D., BCPS3, Susan C. Bleasdale, MD2,4, Ying P. Tabak, PhD3 and Richard S Johannes, MD, MS3,5, (1)Pharmacy Practice, University of Illinois at Chicago, Chicago, IL, (2)University of Illinois Hospital and Health Sciences System, Chicago, IL, (3)Becton, Dickinson and Company, Franklin Lakes, NJ, (4)Medicine, University of Illinois at Chicago, Chicago, IL, (5)Harvard Medical School, Boston, MA

Disclosures:

A. E. Gross, None

V. Gupta, Becton Dickinson: Employee , Salary

S. C. Bleasdale, None

Y. P. Tabak, Becton Dickinson: Employee , Salary

R. S. Johannes, Becton Dickinson: Employee , Salary

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