P744 Epidemiology, clinical characteristics, evolution and treatments in newly diagnosed inflammatory bowel disease (IBD): Results from the nationwide EpidemIBD study of GETECCU

Background Very few studies have reported updated data on the incidence, clinical evolution and treatment of inflammatory bowel disease (IBD) in Europe. Aims i) To assess the incidence of IBD in Spain; ii) to describe the main epidemiological and clinical characteristics of patients at diagnosis and the evolution of the disease; and iii) to explore the use of drug treatments in the biological era. Methods Prospective and population-based nationwide registry. Adult patients diagnosed with IBD -Crohn’s disease (CD), ulcerative colitis (UC) or IBD unclassified (IBD-U)- during 2017 in all the 17 Spanish administrative regions were included and will be followed-up for 5 years after diagnosis. Treatment was grouped into 5 categories: mesalazine (oral or topical), steroids (intravenous, oral or topical), immunomodulators (thiopurines, methotrexate or cyclosporine), biologics (anti-TNF, vedolizumab or ustekinumab) and surgery. Results 3627 incident cases of IBD diagnosed during 2017 in 108 hospitals covering over 22 millions of adult inhabitants (about 50% of the Spanish population) comprise the study cohort (Table 1). The overall incidence (cases/100.000 person-years) was 16 for IBD, 7.5 for CD, 8 for UC, and 0.5 for IBD-U. Incidence of CD was somewhat higher in Central Spain, while that of UC was higher in Northern Spain (Asturias and Navarra) (Figure 1). About 46% of patients had CD and 50% UC. Diagnosis delay was longer in CD than in UC (5 vs. 2 months, p < 0.01). The proportion of patients with symptoms at diagnosis was higher in UC than CD (94 vs. 89%, p < 0.01). By contrast, those with CD vs. UC had higher frequency of family history of the disease (18 vs. 13%, p < 0.01), tobacco smoking (38 vs. 12%, p < 0.01) and extraintestinal manifestations (12 vs. 6%, p < 0.01). At diagnosis, 18% of CD patients had structuring or fistulising behaviour, and 69% of UC patients had extensive colitis or left-sided colitis. During a median of 12-month of follow-up, 28% of patients were hospitalised (35% of CD and 22% of UC patients, p < 0.01). A total of 2.6% CD patients progressed to a more severe phenotype, and 2% UC patients developed a more extensive involvement. The cumulative exposure to different treatments is shown in Figure 2. Conclusion The incidence of IBD in Spain is quite high and similar to that reported in Northern Europe. IBD patients require the use of substantial therapeutic resources, which are greater in CD than in UC, and much greater than previously reported. One third of patients are hospitalised in the first year after diagnosis and over 5% undergo surgery. These results highlight the high burden of IBD as well as some of the important challenges faced by clinicians and healthcare systems to manage this costly and complex disease.