Characteristics and Outcomes of Over a Million Patients with Inflammatory Bowel Disease in Seven Countries: Multinational Cohort Study and Open Data Resource

Background and Aims: Observational healthcare data are an important tool for delineating patients’ inflammatory bowel disease (IBD) journey in real-world settings. However, studies that characterize IBD cohorts typically rely on a single resource, apply diverse eligibility criteria, and extract variable sets of attributes, making comparison between cohorts challenging. We aim to longitudinally describe and compare IBD patient cohorts across multiple geographic regions, employing unified data and analysis framework. Methods: We conducted a descriptive cohort study, using routinely collected healthcare data, from a federated network of data partners in sixteen databases from seven countries (USA, UK, France, Germany, Japan, Korea, and Australia); and computed the prevalence of thousands of attributes, across multiple baseline and follow-up time windows, for full disease cohorts and various strata. Results: Characterizing the disease trajectory of 462,502 Crohn’s disease (CD) and 589,118 ulcerative colitis (UC) subjects, we observed a decline over time in the average age at CD diagnosis in Europe and North America but less pronounced shifts in Japan and Korea; an uptick in the proportion of patients with anxiety diagnosis prior to CD diagnosis in European and US datasets; and stable rates of segmental colonic and small bowel resections within one and three years following UC and CD diagnosis, respectively, in most US databases. Conclusions: The study provides a comprehensive characterization of IBD patient cohorts from various countries including insights into disease trends, demographics, and pre-diagnosis symptoms. All characteristics and outcomes are publicly available, providing an unprecedented, comprehensive open resource for clinicians and researchers.