Development of a Core Outcome Set for Real-world Data in Inflammatory Bowel Disease: A European Crohn's and Colitis Organisation [ECCO] Position Paper

Background and Aims The utility of real-world data is dependent on the quality and homogeneity of reporting. We aimed to develop a core outcome set for real-world studies in adult patients with inflammatory bowel disease [IBD]. Methods Candidate outcomes and outcome measures were identified and categorised in a systematic review. An international panel including patients, dietitians, epidemiologists, gastroenterologists, nurses, pathologists, radiologists, and surgeons participated in a modified Delphi consensus process. A consensus meeting was held to ratify the final core outcome set. Results A total of 26 panellists from 13 countries participated in the consensus process. A total of 271 items [130 outcomes, 141 outcome measures] in nine study domains were included in the first-round survey. Panellists agreed that real-world studies on disease activity should report clinical, endoscopic, and biomarker disease activity. A disease-specific clinical index [Harvey-Bradshaw Index, Partial Mayo Score, Simple Clinical Colitis Activity Index] should be used, rather than physician global assessment. In ulcerative colitis [UC], either the UC Endoscopic Index of Severity or the Mayo Endoscopic Score can be used, but there was no consensus on an endoscopic index for Crohn's disease, nor was there consensus on the use of the presence of ulcers. There was consensus on using faecal calprotectin and C-reactive protein. There was no consensus on the use of histology in real-world studies. Conclusions A core outcome set for real-world studies in IBD has been developed based on international multidisciplinary consensus. Its adoption will facilitate synthesis in the generation of real-world evidence.