The Rising Burden of Inflammatory Bowel Disease in Denmark Over Two Decades: A Nationwide Cohort Study.

Shifts in epidemiological stages of inflammatory bowel disease (IBD) carry implications toward understanding IBD etiology and managing clinical care. We conducted a temporal analysis of the epidemiology of IBD between 1995 and 2016 in the Danish nationwide cohort. We used the Danish registers to obtain data on demographics and IBD-related outpatient and inpatient contacts between 1995 and 2016. IBD diagnosis was defined as having ≥2 registrations related to Crohn's disease (CD) or ulcerative colitis (UC) within a 2-year period. We estimated overall and annual incidence rates and prevalence of CD and UC standardized with respect to age and sex. A total of 47,830 individuals met the criteria for IBD diagnosis, of which 33% were diagnosed with CD and 67% with UC. Between 1995 and 2016, the incidence rate (95% confidence interval) per 100,000 person-years rose from 9.1 (8.3–10.0) to 17.8 (16.8–19.0) for CD, and from 21.0 (19.8–22.3) to 28.4 (27.0–29.8) for UC. The highest increase in CD and UC incidence rates occurred in children and young adults, respectively. The prevalence of IBD doubled from 1995 to 2016; the greatest increase (2.5-fold) was in UC prevalence among individuals aged >40 years. During this period, the median age of the IBD population increased by 6 to 7 years. In Denmark, the incidence and prevalence of IBD have increased during the last 2 decades. The IBD population is shifting toward an older age. These findings have implications towards understanding environmental shifts as well as preparing health care systems for an aging IBD population. [Display omitted] Analysis of Danish nationwide data with follow-up over 2 decades show that inflammatory bowel disease incidence and prevalence are increasing and that the inflammatory bowel disease population is shifting toward an older age. [ABSTRACT FROM AUTHOR]