Change in Prevalence of Family History During Long-term Follow-up of Patients With Pediatric-onset Inflammatory Bowel Disease.

Objectives: The aim of the study was to prospectively study changes in prevalence of positive family history (FH+) in pediatric-onset inflammatory bowel disease (IBD) in contrast to previously published cross-sectional data.

Methods: An observational cohort study was performed using a prospective pediatric-onset IBD database including 485 patients with disease duration ≥10 years as of December 2016. Proband characteristics and FH+ were obtained at diagnosis and subsequently from the database, medical records, and follow-up telephone interviews in 2006 and 2016.

Results: Updated 2016 information was obtained from 322 (66%) patients and included in analysis with median follow-up of 18 years (interquartile range 14, 26). Prevalence of FH+ increased from 13.7% at diagnosis to 26.6% at 20 years for first-degree relatives and from 38.5% to 52.2% for all relatives. At 20-year follow-up, an additional 10.0% of probands had a sibling, 6.1% had a parent, 1.9% had a grandparent, and 4.5% had a cousin diagnosed with IBD. FH+ at diagnosis was associated with greater risk for additional FH+ at 20 years (43% vs 22%, P < 0.001). Non-Jewish Caucasians had significantly lower risk of a FH+ compared to Jewish Caucasians (P = 0.002), but similar risk to African Americans (P = 0.55). FH+ at diagnosis was not associated with disease type (P = 0.33) or age at diagnosis (P = 0.24).

Conclusions: This prospective study documents changes in family history of IBD in pediatric-onset IBD patients over time. Prevalence of FH+ increased for first-degree and all relatives at 20 years by 12.9% and 13.7%, respectively. FH+ at diagnosis was associated with a 2-fold greater likelihood of subsequent FH+ at 20 years.