Inflammatory Bowel Disease in the Post-STRIDE II Era: Epidemiology and Long-term Clinical Outcomes from a Population-Based Study

Background/Objectives: Inflammatory bowel diseases (IBD) include Crohn’s disease (CD) and ulcerative colitis (UC). The availability of an increasing number of new mol-ecules approved for IBD treatment has increased our ability and aspirations to change their natural history. The STRIDE II consensus is the current established suggested strategy for IBD management. Primary objective of this study is to describe the clinical history of IBD in post-STRIDE era, and to quantify the burden of IBD in terms of hos-pitalization rate. Secondary objective is to estimate the 5-years risk of intestinal resec-tion among IBD patiesnts. Methods: Observational time series analysis was conducted on population data; retrospective data from Jan 2011 was collected for Local Health Authority “Roma 1” population (circa 1.5 million residents). Prospective data from hospitalizations among residents since Jan 2018 was also collected. Hospitalization and surgery events among newly diagnosed patients (n= 556) were collected and pro-spectively followed since Jan 2018. Kaplan-Mayer survivor functions were proposed, considering surgical intervention as primary outcome. Results: Current IBD preva-lence is estimated to be 218 (77.2 CD, 141.1 UC) cases/100,000ppl. Incidence trend slowly increased during the last decade up to 5.3 (CD) and 9.4 (UC) cas-es/100,000ppl/year. Yearly hospitalization remained constant near 16.5%, while 6-years risk of surgery is 36% for CD, and 20% for UC. Conclusions: Incidence of IBD increased in the last decades, with substantial stability in the incidence of surgeries and hospitalizations. Thus, current IBD management has only a small effect on changing the natural history of the disease.