Incidence and Prevalence of Paediatric Inflammatory Bowel Disease Continues to Increase in the South of England.

Abstract

The incidence of paediatric inflammatory bowel disease (IBD) has been increasing over 25 years; however, contemporary trends are not established and the impact of COVID-19 on case rates is unclear. Data from Southampton Children's hospital prospective IBD database were retrieved for 2002-2021. Incidence rates were calculated based on referral area populations and temporal trends analysed. Disease prevalence for those aged <18 years was calculated for 2017-2021. Monoclonal prescriptions were reported. In total, 1150 patients were included (mean age at diagnosis 12.63 years, 40.5% female). An estimated 704 patients had Crohn's disease (61.2%), 385 had ulcerative colitis (33.5%), and 61 had IBD unclassified (5.3%). Overall IBD incidence increased, β = 0.843, P = 3 × 10 -6 , driven by Crohn's disease, β = 0.732, P = 0.00024 and ulcerative colitis, β = 0.816, P = 0.000011. There was no change in IBDU incidence, β = 0.230, P = 0.33. From 2002-2021, 51 patients were diagnosed <6 years of age, 160 patients aged 6 to <10 years and 939 patients aged 10 to <18 years of age. Increased incidence was observed in patients aged 10 to <18 years of age (β = 0.888, P = 1.8 × 10 -7 ). There was no significant change in incidence of IBD in <6 years (β = 0.124, P = 0.57), or 6 to <10 years (β = 0.146, P = 0.54). IBD prevalence increased by an average of 1.71%/year from 2017 to 2021, β = 0.979, P = 0.004. The number of new monoclonal prescriptions increased from 6 in 2007 to 111 in 2021. IBD incidence continues to increase in Southern England. Compounding prevalence and increased monoclonal usage has implications for service provision.