The Scoop on Poop Sampling Collection: Awkward Lessons Learned From a Community-Based Trial

Objectives: To explore impacts of varied stool sample collection strategies on clinical trial recruitment and enrollment in a community-based clinical trial. Methods: Data on participant recruitment and enrollment from an ongoing randomized control trial has been examined for this research. We examined data from the Keiki Produce Prescription (KPRx) trial, which is testing the effect of a 6 month produce prescription program on diet, household, gut microbiome and health outcomes of 100 parent-child dyads. Participant recruitment began in September 2022. Waianae Coast Comprehensive Health Center (WCCHC) clinic providers and staff referred eligible children to the study. A research staff followed up on referrals to enroll. Detailed records on referral dates, dates of contact, reasons for declining enrollment, and dates of enrollment were maintained. Study protocol was adjusted to make stool sample provision optional and to increase incentives for stool samples ($50) in August 2023 due to delays in recruitment. Impacts of protocol changes on enrollment were evaluated using records to determine percentage of referred participants who were enrolled, duration between study referral to enrollment (days), and commonly cited reasons for not enrolling. T-tests were performed to assess differences in duration between study referral and enrollment. Results: <127 referrals were examined, 76 declined participation (60%) and 51 enrolled (40%). Referral success rate was 38% prior to the study protocol change and 39% post. Mean days between referral and enrollment was 62.4 days (n=51) which differed pre- and post protocol adjustment, 126.9 days (n=20) vs 18.7 days (n=31) (p< 0.001), respectively. Common issues regarding stool sample collection included, where the kits would be analyzed, access to child samples for school aged children who have bowel movements at school, and older children less willing to allow parents to collect samples. The research staff also noted increased participation in the optional stool sample with the increased incentive. Conclusions: Collecting pediatric stool samples may significantly extend recruitment timelines for research studies. Adjusting timelines and increasing incentives can support the success of researchers. Funding Sources: National Institute of General Medical Sciences, National Institutes of Health.