Reduction in testing and change in testing algorithm associated with decrease in number of nosocomial Clostridioides (Clostridium) difficile infections.

OBJECTIVE

To evaluate the effects of a best practice advisory (BPA) and a change in the Clostridioides (Clostridium) difficile testing algorithm on nosocomial C. difficile infection (CDI) rates.

METHODS

This was a retrospective analysis at a tertiary care hospital of adult patients who tested positive for CDI between July 1, 2017 and September 30, 2019. In June 2018, we implemented a BPA in our electronic health record recommending against testing for CDI in patients receiving laxatives. We reviewed the number of C. difficile tests ordered before and after initiating the BPA. In December 2018, we replaced nucleic acid amplification testing (NAAT) with a cell cytotoxicity assay (CCA) for stool specimens that were enzyme immunoassay toxin negative and glutamate dehydrogenase positive.

RESULTS

The number of C. difficile tests ordered per month decreased 14% after implementing the BPA (P = .0001). Following this intervention, the rate of nosocomial CDI (nCDI) decreased by 16.5% (P = .33). Following substitution of CCA for NAAT for enzyme immunoassay toxin-/glutamate dehydrogenase+ specimens, there was a 50% reduction in the rate of nCDI (7.1 cases/10,000 patient days to 3.5 cases/10,000 patient days; P < .0001).

CONCLUSIONS

Implementing a BPA to reduce inappropriate testing and changing the testing algorithm for C. difficile by substituting CCA for NAAT resulted in a lower rate of diagnosis of nCDI.