Evaluation of the clinical performance of a multistep algorithm for the diagnosis of Clostridioides difficile infection and patient characteristics in a clinical setting

Background: Clostridioides difficile infection (CDI) is a significant cause of antibiotic-associated diarrhea and colitis. The diagnosis of CDI relies on clinical presentations confirmed by laboratory investigations. Objectives: This study aimed to evaluate the performance of current diagnostic tests and examine the characteristics of patients associated with CDI in a real hospital setting. Methods: A total of 299 unformed stool specimens were collected and analyzed using the C. DIFF QUIK CHEK COMPLETE and PCR assays. Patient data were retrospectively reviewed from medical records. Results: The C. DIFF QUIK CHEK COMPLETE and PCR assays detected toxigenic C. difficile in 16/299 (5.4%) and 37/299 (12.4%) specimens, respectively. The agreement between these two assays for detecting C. difficile and toxin A/B was 90.3% and 93.0%, respectively. Utilizing a multistep algorithm with the C. DIFF QUIK CHEK COMPLETE assay, arbitrated by the PCR assay, significantly increased the detection of toxigenic C. difficile (p < 0.05). Among the clinical characteristics of patients, age over 60 years was significantly associated with CDI (p < 0.05). However, the duration of antibiotic exposure and the type of antibiotics were not significantly different between patients with and without toxigenic C. difficile. Additionally, inappropriate use of C. difficile diagnostic tests and treatments was common among patients presenting with diarrhea from other causes and a history of antibiotic exposure. Conclusions: A multistep algorithm is a valuable diagnostic tool for CDI, particularly in hospitals lacking established testing criteria. Effective stewardship of C. difficile testing is essential to prevent the inappropriate utilization of laboratory resources.