Implementation of multifaceted diagnostic stewardship for Clostridioides difficile infection during the COVID-19 pandemic at a small Japanese hospital

infection (CDI) is a common, healthcare-associated infection. However, in Japan, testing for CDI is infrequent, suggesting that its incidence may be underestimated. This study aimed to examine the implementation of a multifaceted, diagnostic stewardship (DS) for CDI in a small Japanese hospital during the coronavirus 2019 pandemic. Before-after study. A small Japanese community hospital. Healthcare workers including physicians, nurses, and pharmacists. A multifaceted intervention including (1) the addition of CD testing criteria to the hospital guidelines; (2) provision of a tutorial on CD testing to physicians, nurses, and pharmacists; (3) assessment by clinical pharmacists and nurses of the need for CD testing in patients with nosocomial diarrhea and issuance of recommendations for CD testing to physicians; (4) reporting of data on the CD testing rate and CDI incidence in the study center. The CD testing rate increased before the pandemic (+0.16/10,000 patient-days (PD); = .28), decreased significantly during the pandemic (-0.79/10,000 PD; = .02), and then increased significantly immediately after the implementation of the intervention (+29.6/10,000 PD; < .01). Similarly, the CDI incidence increased significantly before the pandemic (+0.26/10,000 PD; = .02) and decreased significantly during the pandemic (-0.49/10,000 PD; = .01). Implementation of the intervention resulted in an immediate and significant increase in the CDI incidence (+6.2/10,000 PD; < .01). Multifaceted DS involving multidisciplinary specialists was effective in improving CD testing, suggesting that appropriate testing can contribute to diagnosing CDI accurately.