Nursing-Led Support Across the Standard Care-Clinical Trial-Standard Care Pathway in Inflammatory Bowel Disease: A Review With Realist-Informed Interpretation.

AIMS: To examine how nursing-led support may influence engagement, continuity, adherence, retention, and protocol enactment across the standard care-clinical trial-standard care pathway in individuals with inflammatory bowel disease (IBD). METHODS AND RESULTS: This focused narrative review used selected realist-informed interpretive principles as a conceptual lens to synthesize heterogeneous literature related to IBD clinical trials, specialist and clinical research nursing, placebo and nocebo processes, health literacy, teach-back, telemonitoring, continuity of care, transitions, implementation, and intervention fidelity. Rather than conducting a formal realist review, realist concepts were used to inform the interpretation of how contextual factors, participant reasoning, and implementation conditions may influence nursing-led support across the clinical trial pathway. Literature was identified through iterative searches in PubMed/MEDLINE, Scopus, and Google Scholar, complemented by backward and forward citation tracking. Five interrelated supportive functions emerged across the reviewed literature: expectation-shaping during screening and enrolment; literacy-sensitive education and teach-back; structured hybrid contact and continuity support; transition-sensitive assistance during trial entry, amendment, and exit phases; and governance strategies promoting role clarity, safety, and equity. Nursing-led support appeared most relevant when it helped participants interpret uncertainty, understand protocol expectations, maintain continuity, and navigate vulnerable transitions. These functions may contribute to engagement, adherence, retention, and timely symptom reporting by strengthening trust, self-efficacy, relational continuity, and adherence to practical protocols. CONCLUSION: Nursing-led support may represent a potential mechanism-bearing component of IBD clinical trial participation rather than a purely administrative activity. Transition-sensitive, literacy-aware, and continuity-oriented nursing strategies may support safer, more equitable, and more sustainable engagement across increasingly complex clinical trial pathways.