Treatment Patterns, Extra-Intestinal Manifestations, Resource Utilisation, and Outcomes of Patients With Inflammatory Bowel Disease in Dutch Hospitals

Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a chronic, relapsing inflammatory disorder of the gastrointestinal tract with an increasing global burden. Patients frequently require lifelong management and may experience substantial healthcare resource utilization (HCRU) throughout the course of their disease. Beyond intestinal symptoms, many patients develop extra-intestinal manifestations (EIMs), including rheumatological, dermatological, ophthalmological, and pulmonary conditions, which further increase disease complexity and healthcare burden.

Over the past decade, therapeutic options for IBD have expanded considerably. In addition to conventional treatments such as corticosteroids, thiopurines, methotrexate, and aminosalicylates, multiple classes of advanced systemic therapies (ASTs) are now available, including anti-TNF agents, anti-integrin therapies, anti-IL-12/23 therapies, JAK inhibitors, and S1P receptor modulators. Despite these advances, long-term remission remains challenging for many patients, and there is limited real-world evidence describing how therapies are used in routine Dutch clinical practice, including treatment sequencing, treatment duration, healthcare resource utilization, and outcomes associated with EIMs.

This study aims to address these evidence gaps by generating real-world insights into treatment patterns, EIM burden, healthcare utilization, and costs among patients with CD and UC treated in Dutch hospitals. The findings are intended to support clinical decision-making, healthcare planning, and future research on IBD management in the Netherlands.

Study Design Retrospective, observational, multicenter real-world data cohort study using routinely collected healthcare data from 5 to 10 participating Dutch hospitals. The observational period runs from 1 January 2018 through 31 July 2026 and is fully closed prior to any data extraction. Data are extracted and pseudonymized within participating hospitals before transfer for analysis. No patient contact occurs and no additional data are collected.

Data sources include administrative and claims data, diagnosis registrations, prescription data, electronic prescribing system (EVS) data, laboratory databases, surgical and endoscopy activity data, and intramural medication records. Laboratory data may include fecal calprotectin (fCal), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), serum albumin, and therapeutic drug monitoring results.