Inflammatory bowel disease in South-Eastern Norway III (IBSEN III): a new population-based inception cohort study from South-Eastern Norway

Abstract

Background and aim

Modern treatment strategies for inflammatory bowel disease (IBD) are postulated to change the natural disease course. Inception cohort studies are the gold standard for investigating such changes. We have initiated a new population-based inception cohort study; Inflammatory bowel disease in South Eastern Norway III (IBSEN III). In this article, we describe the study protocol and baseline characteristics of the cohort.

Methods

IBSEN III is an ongoing, population-based observational inception cohort study with prospective follow-up. Adult and pediatric patients with suspected IBD in the South-Eastern Health Region of Norway (catchment area of 2.95 million inhabitants in 2017), during the 3-year period from 2017 to 2019, were eligible for inclusion. Comprehensive clinical, biochemical, endoscopic, demographic, and patient-reported data were collected at the time of diagnosis and throughout standardized follow-up. For a portion of the patients, extensive biological material was biobanked.

Results

The study included 2168 patients, of whom 1779 were diagnosed with IBD (Crohn’s disease: 626, ulcerative colitis: 1082, IBD unclassified: 71). In 124 patients, there were subtle findings indicative of, but not diagnostic for, IBD. The remaining 265 patients were classified as symptomatic non-IBD controls.

Conclusion

We have included patients in a comprehensive population-based IBD cohort from a catchment population of 2.95 million, and a unique biobank with materials from newly diagnosed and treatment-naïve IBD patients and symptomatic non-IBD controls. We believe this cohort will add important knowledge about IBD in the years to come.

Keywords:

• Crohn’s disease
• inflammatory bowel disease
• ulcerative colitis

Acknowledgements

The authors thank all the study nurses and local study personnel who have contributed to the inclusion of patients in the IBSEN III study. We also thank the Clinical Trial Unit, Division of Medicine, Akershus University Hospital, and Unger-Vetlesen Institute, Department of Medicine, Lovisenberg Diaconal Hospital, for their contributions to the collection and handling of the biobank material.

Author contributions

Study conception: MLH. Study design: MLH, VAK, RO, GP, GHH, SB, PR. Collection of data: All authors. Statistical analyses, interpretation of data and draft of the manuscript: VAK, MLH. Critical revision of the manuscript for intellectual content: All authors. Approval of the final manuscript: All authors.

Disclosure statement

The authors report no conflict of interest.

Data availability statement

The data underlying this article cannot be shared publicly due to the privacy of individuals that participated in the study. The data will be shared on reasonable request to the corresponding author.

Additional information

Funding

IBSEN III is fully investigator-initiated and has received funding from the following sources: Takeda Pharmaceuticals, Pfizer, Ferring Pharmaceuticals, Tillotts Pharma, Dam Foundation, and the South-Eastern Health Authorities.