Microbiota or placebo after antimicrobial therapy for recurrent Clostridioides difficile at home: A clinical trial with novel home-based enrollment.

INTRODUCTION: Clostridiodes difficile infection is the leading cause of infectious diarrhea in the United States, with substantial morbidity and mortality. Recurrent infection is especially challenging, with each recurrence increasing the likelihood of a successive recurrence, leading to cycles of prolonged symptoms, frequent antimicrobial use, and decreased quality of life. Fecal microbiota transplantation to prevent recurrent infection is a promising intervention with a large effect size in observational studies, but with conflicting results from randomized controlled trials. We are conducting a Veterans Affairs-wide randomized controlled trial utilizing centralized case identification, with enrollment and fecal microbiota transplant administration occurring at the participant's home. This type of trial design significantly improves trial efficiency, greatly decreases trial cost, increases consistency of trial administration, and most importantly makes nationwide clinical trials in less-common diseases possible. METHODS: This is a randomized comparison of capsule-delivered fecal microbiota transplant for the prevention of recurrent Clostridiodes difficile infection, administered after successful initial treatment of recurrent C. difficile infection with standard therapy. The primary endpoint is the incidence of recurrent C. difficile infection or death. Cases are identified by searching the Veterans Affairs Corporate Data Warehouse, with central study coordinators then reaching out to potential participants. Individuals meeting inclusion criteria and interested in participation are scheduled for in-home consent, randomization, and capsule administration, followed by telephone follow-up for 6 months. To mitigate risks of COVID-19, enrollment via video visits has been implemented. RESULTS: A total of 102 participants have been enrolled through January 2021. Centralized case identification and in-home enrollment has facilitated enrollment from 34 unique states, with 38% being from rural or highly rural areas. DISCUSSION: Centralized case identification and in-home enrollment is a feasible and innovative method of conducting randomized controlled trials in the Veterans Affairs system, improving access to clinical research for populations who may have difficulty engaging with the traditional model of clinical trials where enrollment is based at large hospitals in major metropolitan areas.