Epidemiology of Elderly Onset IBD: A Nationwide Population-Based Cohort Study.

Background and aims: We examined the incidence and natural history of patients with very elderly onset (herein referred to as very late-onset) inflammatory bowel diseases (IBDs) (≥ 70 years of age at diagnosis), compared with patients diagnosed between 60 and 69 years of age in Denmark.

Methods: In the Danish National Patient Register, between 1980 and 2018, we identified all individuals ≥ 60 years of age with newly diagnosed Crohn's disease (CD) and ulcerative colitis (UC) and examined trends in incidence, cumulative risk of hospitalization, treatment patterns, IBD-related surgery, serious infection, cancer and cardiovascular and venous thromboembolic risks among very late-onset (70-79 years of age or 80+ years) vs late-onset (60-69 years of age) IBD, using nonparametric competing risk analysis treating death as competing risk.

Results: We identified 3459 patients with onset of CD at ≥60 years of age (47% ≥ 70 years of age) and 10,774 patients with onset of UC ≥60 years of age (51% ≥ 70 years of age). Over the last 3 decades, incidence changes for very late-onset and late-onset IBD have followed the same patterns. Also, both for CD and UC, cumulative incidence of IBD-related hospitalization and corticosteroid use was comparable in very late-onset vs late-onset patients. However, the burden of disease-modifying therapy, either immunomodulator or tumor necrosis factor antagonist use, and major IBD-related surgery was significantly lower in patients with very late-onset than in late-onset IBD. On the other hand, the 5-year risk of serious infections and cardiovascular events was higher in patients with very late-onset IBD.

Conclusions: This nationwide cohort study shows that patients diagnosed with very late-onset (≥ 70 years of age) IBD have a higher relative burden of disease- and aging-related complications, with limited use of steroid-sparing strategies and surgery, compared with late-onset IBD.