DOP021 Familial risk of inflammatory bowel disease: a population-based cohort study 1977–2011

Background: Previous systematic reviews have shown the incidence of adult-onset inflammatory bowel disease (IBD) and paediatric-onset IBD (PIBD) are increasing worldwide, particularly in developed countries, however, little is known about PIBD prevalence.The determination of prevalence is crucial to inform effective service provision and delivery and may provide clues to the aetiopathogenesis of IBD.We aimed to assess the available evidence on worldwide prevalence of PIBD, assess geographic distribution and analyse trends using systematic review.Methods: A literature search was performed using MEDLINE (1950 2012), Medline in progress, Cochrane database and EMBASE (1980 2012) to identify relevant population-based studies.Studies were included that reported distinct paediatric prevalence data on total Inflammatory Bowel Disease (IBD), Crohn's disease (CD), Ulcerative colitis (UC), Inflammatory Bowel Disease Unclasssified (IBDU) or any combination of these.Abstracts in all languages were considered but only included if full text was available.Data was extracted on source of prevalence data, age ranges, country of origin, diagnostic criteria and methodology.Results: 4190 references were found and reviewed; 27 studies which presented data on the prevalence of PIBD and/or CD and/or UC from 11 countries were included.No prevalence data were presented on IBDU.The prevalence of PIBD ranged from 6.0 30.0 per 100,000 while CD ranged from 0.5 to 85.3 per 100,000 and UC from 3.0 to 90.1 per 100,000.Only two studies provided trend analysis over time, showing an increasing PIBD prevalence during a 5 and 10-year period respectively.There was a preponderance of reports from developed countries: 8 from North America, 10 from Europe, 5 from the Middle East, 2 from Asia, 1 from Africa, and 1 from Australasia.Prevalence rates were highest in North America and lowest in Africa and Asia.Most studies (74%) were retrospective, used a variety of sources including national registries, insurance databases, retrospective case note review and physician survey.No true population-based studies were reported.Age ranges and diagnostic criteria used varied widely.Conclusions: PIBD prevalence was highest in North America and Europe with little data from developing nations with insufficient data to analyse trends over time.Data was heterogenous in terms of diagnosis of disease, method of case accrual and age ranges making interpretation of prevalence challenging.Well designed studies with clear diagnostic criteria and age ranges would confirm if the increase seen in the worldwide prevalence of adult IBD is mirrored in PIBD which can then be used to enhance clinical service provision and drive future funding for research.