IBD in the elderly population: Epidemiology, long-term disease course, surgery rates and biological use - data from the Veszprem county cohort between 1977-2020. Journal of Crohn's & colitis BACKGROUND AND AIMS:Limited data are available on long-term disease outcomes in elderly-onset (EO) inflammatory bowel diseases (IBD) from well-defined population-based cohorts. Our aim was to analyze incidence, disease course, surgery rates and therapeutic strategies of EO IBD in a prospective population-based cohort. METHODS:EO IBD was defined if diagnosis was established at ≥60years of age. Patient inclusion lasted between 1977 and 2018. Study endpoints were compared between elderly- and adult-onset (AO) patients, and different therapeutic eras. Data from medical records were prospectively collected and regularly reviewed, as part of the well-established Veszprem IBD cohort. RESULTS:Data of 946 Crohn's disease(CD) and 1,370 ulcerative colitis(UC) patients were analyzed. The proportion of EO CD and UC patients were 6.1% (58/946) and 13.4% (183/1,370) in the total cohort. Biological therapy exposure was significantly lower in EO CD compared to AO [pLogRank=0.003], but similar exposure was seen amongst UC patients [pLogRank=0.770]. Early surgery rates (≤1 year from diagnosis) were significantly higher in EO CD patients compared to AO (27.6% vs15.6%; p<0.001). However, there was no statistically significant difference in overall resective surgery rates between the EO and AO cohorts in CD [pLogRank=0.838], nor colectomy rates differed in UC [pLogRank=0.435]. Disease phenotype progression in CD and UC were both lower in EO disease [pLogRank=0.015; pLogRank=0.022]. CONCLUSION:EO IBD represent an increasing proportion of IBD patients, with high exposure to biologicals in EO UC. Overall surgery rates were similar in EO and AO cohorts, however early surgeries in CD were higher in EO patients. 10.1093/ecco-jcc/jjaf003