Evaluation of Antibiotic Use Metrics as Predictors of Clostridioides difficile Infection Onset: A Single-Center, Case–Control Study Assessing the Days of Therapy and the Days of Antibiotic Spectrum Coverage

Excessive antibiotic use is a well-known risk factor for the onset of Clostridioides difficile infection (CDI). This study aimed to assess whether antibiotic use metrics such as the days of antibiotic spectrum coverage (DASC), days of therapy (DOT), and patient antibiotic day (PAD) are useful in predicting the onset of first-episode CDI. A single-center, retrospective, case-control study was conducted at Showa Medical University Hospital. Patients who exhibited an initial episode of CDI (first CDI toxin-positive test result after admission) in our hospital were classified as the case group. Those who obtained CD toxin-negative test results without diarrhea belonged to the control group. A total of 173 patients were included, with 110 in the case group and 63 in the control group. The median values of DASC, DOT, and PAD were significantly higher in the case group than in the control group (54 vs. 120.5, 6.0 vs. 13.0, and 5.0 vs. 11.0, respectively; all: p < 0.05). In a receiver operating characteristic analysis involving DASC, DOT, and PAD, the area under the curve ranged from 0.620 to 0.639. In conclusion, metrics reflecting the duration of antibiotic administration and the antibiotic spectrum appeared to be significant predictors of CDI onset. These findings further support the importance of monitoring these metrics and minimizing the duration of antibiotic use and the use of broad-spectrum agents.