Impact of Systematizing Severity Evaluation on the Treatment of <i>Clostridioides difficile</i> Infection

The 2018 Clostridioides difficile infection (CDI) treatment guidelines recommend the selection of therapeutic agents based on the severity and recurrence of CDI. To optimize the selection of CDI treatment agents, we systematized the evaluation methods for the severity and recurrence of CDI and integrated them into the prescription order system. This study reports changes in CDI cure rates and therapeutic agent selection associated by introducing a new system. This study included patients diagnosed with CDI who received treatment between March 2015 and April 2023. According to the CDI treatment guidelines, the selection rates of first-choice drugs were 96.7％ and 4.8％ for nonsevere and severe patients, respectively, at initial onset in the preintroduction group (before the new system was introduced). The selection rates were 98.0％ and 90.0％ for nonsevere and severe patients, respectively, in the postintroduction group. The rates of recurrent patients were 38.9％ and 95.2％ in the pre- and post-introduction groups, respectively. However, the cure rates for nonsevere and severe patients at initial onset were 76.3％ and 52.4％, respectively, in the preintroduction group, and 82.0％ and 70.0％, respectively, in the postintroduction group. Recurrence rates were 55.5％ and 81.0％ in the pre- and post-introduction groups, respectively. According to the CDI treatment guidelines, the implementation of a system for evaluating the severity and recurrence of CDI while selecting treatment drugs considerably improved the selection rate of the first-choice drug, according to the CDI treatment guidelines. However, this did not affect the cure rates.