BACKGROUND: Easily accessible predictors of disease course in inflammatory bowel disease (IBD) are scarce, and it remains largely unknown whether a family history of IBD predicts the course of Crohn's disease (CD) and ulcerative colitis (UC). We aimed to compare the course of disease in familial and sporadic cases of IBD in a nationwide cohort study.
METHODS: From national registries, covering a population of 8,295,773 individuals, we obtained information on date and year of diagnosis of IBD cases, gender, age, and family ties. Using Cox regression, we estimated hazard ratios for IBD-related hospitalization, biological treatment, and surgery in familial versus sporadic cases of IBD.
RESULTS: A total of 27,886 IBD cases, including 1006 IBD-relative pairs, were followed-up for up to 16 years, totaling 164,979 person-years. We observed no difference in risk of hospital admissions between familial and sporadic cases of IBD. However, patients with familial CD had significantly higher risk of major surgery than sporadic CD cases after 2 years of disease duration (hazard ratio, 1.62; 95% confidence interval, 1.26-2.07). Also, sensitivity analysis suggested a slightly reduced time from diagnosis to first tumor necrosis factor-α inhibitor treatment among familial CD and UC cases as compared with sporadic cases.
CONCLUSION: We found only minor differences in surgery rates and tumor necrosis factor exposure, between familial and sporadic cases of IBD. These findings may represent purely social rather than functional effects, which is consoling for newly diagnosed CD or UC patients with a family history of IBD.