Redesigning a faster pathway to IBD diagnosis (RAPID): Can direct-to-public laboratory testing using stool biomarkers reduce the time to diagnosis of IBD?

Research Question: Can direct-to-public stool testing be used to reduce the time to diagnosis of inflammatory bowel disease in young people experiencing chronic lower gastrointestinal symptoms? Background: One-quarter of patients report symptoms for over a year before a diagnosis of Inflammatory Bowel Disease (IBD)2. Why people wait so long before seeking help is unclear. Embarrassment and apprehension of invasive tests are common13. Timely diagnosis of IBD is important because earlier use of biologic therapies leads to mucosal healing, a reduction in hospitalisations and surgeries and improvements in quality of life3,4. Aims: To define the diagnostic value of Faecal Immunochemical Testing(FIT) for detecting inflammatory bowel disease. To define the time-to-diagnosis of IBD over 1-year and identify factors associated with diagnostic-delay. To identify common barriers to IBD diagnosis. To investigate whether direct-to-public stool testing within a secondary care pathway can reduce time-to-diagnosis in IBD. Methods: Using the Clinical Practice Research Datalink(CPRD), primary and linked secondary healthcare datasets, I will define the diagnostic value of FIT testing for detecting inflammatory bowel disease and other serious GI pathology, in an age stratified cohort. RAPID-1: 200 people with new diagnosis of IBD at the Royal Devon and Exeter NHSFT will be invited to complete questionnaires related to their diagnostic pathway, and impact of their IBD on fatigue, mood and quality of life at the point of diagnosis. A purposive sample of around 30 participants will be invited to semi-structured interview. Thematic analysis will be used to identify common barriers to IBD diagnosis. RAPID-2: 5000 stool tests will be available to 16-49 year olds in East Devon, who report unexplained lower gastrointestinal symptoms for more than 2 weeks. Tests will be marketed by a dedicated media strategy informed by RAPID-1, and orderable through an online portal or via phoneline request. Samples will be assayed for calprotectin and FIT testing, against predefined positivity thresholds. Patients with a positive test will be offered urgent clinic review and investigations. Participants in RAPID-1 and RAPID-2 will be followed up for 1 year, for clinical outcomes and missed diagnoses. By comparing the two cohorts I will determine if direct-to-public stool testing can reduce the proportion of people waiting more than 4 months for a diagnosis of IBD. Combined with wider service evaluation data, this will inform the merit of further evaluation, of a direct-to-public testing pathway.