Diagnostic Stewardship on the Extra-Analytical Phase to Secure Quality Assurance of Diagnostic Tests for Clostridioides difficile Infection

ABSTRACT

Background@#Clostridioides difficile infection (CDI) is the most essential cause of antimicrobial-related diarrhea in hospitalized patients. It is also considered as an important hospital-acquired infection. Adequately performing the laboratory diagnostic tests for CDI is critical for the control and treatment of CDI in healthcare facilities. This study focused on the management of the extra-analytical phase to secure quality assurance of the diagnostic tests for CDI. @*Methods@#We analyzed the volume and pattern of requested C. difficile - related tests from patients in 2018. The culture-positive rate was compared with the stool quality. Finally, the clinical characteristics of antibiotic-related diarrhea were compared based on whether toxigenic C. difficile was isolated. @*Results@#Culture plus toxin enzyme immunoassay was the most common pattern; however, it showed low positive rates for toxigenic C. difficile . The culture-positive rates were not different according to the Bristol stool form scale. The significant risk factors for the detection of toxigenic C. difficile in patients with antibiotic-associated diarrhea were inhibitor-combined penicillin or cephalosporin (odds ratio [OR], 5.060; 95% confidence interval [CI], 1.317–19.447; P =0.0183) and extended-spectrum cephalosporin (OR, 16.224; 95% CI, 3.166–83.134; P =0.0008). @*Conclusions@#The pre-pre-analytical errors are easy to overlook in routine laboratory procedures. Our findings could provide a good example of the management of the extra-analytical phase to secure quality assurance of the diagnostic tests for CDI.