Positive impact of a diagnostic stewardship intervention on syndromic panel ordering practices and inappropriate C. difficile treatment.

Objective: Multiplex polymerase chain reaction (PCR) panels for stool testing may be used to diagnose Clostridioides difficile, which can circumvent more appropriate targeted C. difficile testing, resulting in treatment of incidentally detected colonization. We sought to reduce C. difficile diagnosis via a gastrointestinal pathogen panel (GIPP).

Design: Quasi-experimental, pre/post, retrospective cohort study from January 1, 2022, to January 31, 2024.

Setting: Mayo Clinic Arizona-a single academic medical center and associated clinics.

Patients: Adult patients receiving C. difficile testing and/or treatment.

Methods: Preferred C. difficile testing consisted of glutamate dehydrogenase and toxin antigen immunoassay, followed by toxin gene testing for discrepant results. The GIPP contained 22 targets during the baseline period with C. difficile removed during the postintervention period. Surveys were provided to provider and nursing groups, separately, to identify C. difficile ordering practices and knowledge gaps.

Results: At baseline, from January 1, 2022, to January 31, 2023, 2,772 GIPPs were completed for 2,307 unique patients (∼7 per day), primarily for outpatients (1,805 of 2,772, 65%). The most common positive target was C. difficile (517 of 1,018, 51%), which resulted in treatment for C. difficile infection in 94.9% (337 of 355) of cases. Following GIPP C. difficile target removal, GIPP orders decreased from 3.23 to 2.7 per 1,000 patient visits (P < .001). Prescribing of C. difficile treatments decreased in the postintervention period in inpatient and outpatient settings. There were no cases of delayed C. difficile diagnosis during the postintervention period.

Conclusions: Removing C. difficile from the GIPP resulted in effective diagnostic and antimicrobial stewardship without resulting in delayed diagnoses.