Feasibility and Methodological Reflections From the Co-Creation of a Randomized Controlled Trial (The Kid's Trial):...

Limited public understanding of randomized controlled trials (RCTs) hinders recruitment, retention, and confidence in research. Early exposure to trial concepts may strengthen health literacy and research engagement. The Kid's Trial was a global, decentralized, child-led study that cocreated and conducted an RCT to help children understand trials and their importance and to improve critical thinking.

This paper evaluated the feasibility and methodological implications of engaging children in the cocreation and conduct of a fully online RCT.

The Kid's Trial ed a dedicated website guiding children through each step of designing and conducting an RCT. Materials were codeveloped with 2 patient and public involvement groups of children and parents. Any child aged 7-12 years could take part in as many steps as desired. Recruitment combined online and offline strategies, and engagement and self-reported learning were descriptively analyzed. The cocreated Randomized Evaluation of Sleeping With a Toy or Comfort Item (REST) trial was a 2-arm, pragmatic RCT comparing one week of sleeping with a comfort item versus without a comfort item. The primary outcome was sleep-related impairment, and the secondary outcome was overall sleep quality. Analyses followed an intention-to-treat (ITT) approach using mixed effects models adjusted for baseline measures.

Overall, 224 children participated in at least one step of The Kid's Trial. Participation varied: 37% (n=82) completed one step, and 21% (n=48) completed 6 surveys. The REST trial randomized 139 children, with 73% (n=101) completing outcome surveys. Adjusted mean differences (intervention - control) were -0.53 (95% CI -3.40 to 2.34) for sleep-related impairment (P=.71) and 0.28 (95% CI 0.01-0.55) for sleep quality (P=.04). The difference was small and was not supported by sensitivity analyses. Poststudy responses (n=20) suggested improved self-reported trial understanding among respondents but were limited by low response rate and potential selection bias.

The Kid's Trial demonstrates the feasibility of a decentralized, child-led RCT cocreated through participatory citizen-science methods. Children can meaningfully contribute to trial design and conduct, and experiential participation may support engagement with trial concepts. Future studies should enhance engagement through community partnerships, shorter intervals between steps, and embedded learning assessments to improve inclusivity and retention.