Successful Diagnostic Stewardship Intervention in Reducing Unnecessary Stool Testing for Clostridioides difficile in a Veterans Affairs Hospital

Introduction: Clostridioides difficile is a highly transmissible bacterium that causes diarrhea and colitis, particularly in patients recently treated with antibiotics. Because inappropriate testing may identify patients who are colonized rather than infected, the Infectious Diseases Society of America recommends targeted testing only in patients with symptoms consistent with C. difficile infection (CDI). In our institution, we implemented a templated note-order to reduce the increasing rates of tests that identified colonization rather than true infection. Methods: A templated note-order was created in our electronic records and implemented in late 2022. A provider, resident in training, or attending physician must complete this note first to generate an order for stool C. difficile testing. The microbiology laboratory hid the result of the C. difficile polymerase chain reaction (PCR) result, which is part of the GI PCR panel. Only the GDH/C-diff toxin assay can be ordered through the template note. Results: We compared C. difficile testing rates from 2019 to 2022 with those from 2023 to 2025. There was a significant reduction in the median tests ordered (250 vs. 187, P =0.017). A spike in inappropriate testing occurred in 2022, with 13 colonization cases; targeted education for acute care and nursing home staff was provided to reinforce appropriate testing criteria. Our antimicrobial stewardship program, initiated in 2016, has contributed to sustained reductions in CDI. Conclusions: The implementation of a templated note-order significantly reduced unnecessary C. difficile testing and lowered the number of positive results attributable to colonization. Diagnostic stewardship continues to play a critical role in our infection prevention and control efforts.