The following was originally posted by PW blogger Jasmine Marcelin, MD, to the University of Nebraska Medical Center Division of Infectious Diseases blog.


Rapid diagnostic testing (RDTs) plays an important role in Antimicrobial Stewardship Programs (ASP) and highlights the impact of the Microbiology laboratory on reducing inappropriate antibiotic use, particularly in hospitalized patients. Early microbial identification with RDTs can lead to earlier initiation of targeted antimicrobial therapy, which can in turn result in shorter hospitalization, fewer adverse events and reduced C. difficile infections. Other studies have shown that while implementation of RDTs improves outcomes, coupling RDT implementation with ASP increases the impact on clinical care. However, there is still a dearth of published studies relating to ASP in the context of the unique group of immunocompromised patients.  This review described a recently published study evaluating the impact of rapid diagnostic testing on Antimicrobial Stewardship in this patient population.

This single center study in adults admitted to a cancer hospital had a pre-post intervention design, with two intervention arms – implementation of Biofire® Blood Culture ID (BCID) testing to positive blood cultures, and BCID + ASP review (implemented two years after the initial BCID intervention). Addition of BCID led to more appropriate antimicrobial therapy and reduced time to appropriate therapy.  Further addition of ASP review two years after BCID implementation did not provide statistically significant benefit, however, advanced regression analysis of predictedtime to appropriate antibiotic therapy from Gram stain showed that compared to the pre-intervention cohort (38.1hrs), this time decreased to 13.1hrs for the BCID group and 8.3hrs for the BCID+ASP group (P=0.02). Studies in the non-cancer population have shown significant benefit from including ASP with implementation of rapid diagnostic testing for bloodstream infections; in this study however, two years after BCID implementation, clinician familiarity with the rapid diagnostic test may have affected the impact of adding ASP review to the process.  This is a small study with a somewhat heterogeneous niche population of immunocompromised patients; a larger study could potentially produce more significant results, address effect of culture/attitudes to de-escalation for neutropenic fever, and highlight where ASP should be allocated in specific patient populations where resources may be limited.

The preceding was previously posted by Dr. Marcelin to SHEA Journal Club published online in December 2018.