Metronidazole versus Vancomycin for a Moderate Clostridioides difficile Infection Defined by the Japanese Severity Score (MN Criteria): A Propensity Score-Matched Cohort Study

Objective To compare the effectiveness of initial metronidazole (MNZ) and vancomycin (VCM) for moderate Clostridioides difficile infection (CDI), as defined by the Japanese MN criteria. Methods: A single-center retrospective cohort study (2011-2025). Adult inpatients with an initial episode of moderate CDI who received oral MNZ or VCM were identified. Propensity score matching (1:1; caliper 0.2) balanced the demographics, severity indicators, comorbidities, and concomitant medications.