Systematic Analysis of the Impact of Diagnostic Delay on Bowel Damage in Paediatric Versus Adult Onset Crohn’s Disease

Background and Aims Length of diagnostic delay is associated with bowel strictures and intestinal surgery in adult patients with Crohn’s disease [CD]. Here we assessed whether diagnostic delay similarly impacts on the natural history of paediatric CD patients. Methods Data from the Swiss IBD Cohort Study were analysed. Frequency of CD-related complications [bowel stenosis, perianal fistula, internal fistula, any fistula, resection surgery, fistula/abscess surgery, any complication] at diagnosis and in the long term [up to 30 years after CD diagnosis] was compared between paediatric patients [diagnosed <18 years] and adult patients [diagnosed ≥18 years] using multivariate Cox proportional hazard regression modelling. Results From 2006 to 2016, 387 paediatric and 1163 adult CD patients were included. Median [interquartile range: IQR] diagnostic delay was 3 [1–9] for the paediatric and 6 [1–24] months for the adult group, respectively. Adult onset CD patients presented at diagnosis more frequently with bowel stenosis [p <0.001] and bowel surgery [p <0.001] compared with paediatric CD patients. In the long term, length of diagnostic delay was significantly associated with bowel stenosis [p = 0.001], internal fistula [p = 0.038], and any complication [p = 0.024] in the adult onset CD population. No significant association between length of diagnostic delay and CD-related outcomes in the long term was observed in the paediatric population. Conclusions Adult CD patients have longer diagnostic delay compared with paediatric CD patients and present at diagnosis more often with bowel stenosis and surgery. Length of diagnostic delay was found to be predictive for CD-related complications only in the adult but not in the paediatric CD population.