Spatial mapping and geographic variation of inflammatory bowel disease in Canada: a population-based study

Inflammatory bowel disease (IBD) poses significant challenges to healthcare systems, with rising prevalence globally. To address challenges of health resource allocation and understand the geographic distribution of disease in Canada, we explored spatial mapping of IBD across Canada.

Data from 2009 to 2018 Canadian Community Health Survey identified individuals with IBD. Crude and adjusted prevalence rates were calculated, and spatial dependencies were analyzed using Moran's I. Local indicators of spatial association identified hot-spots where the prevalence of IBD was significantly different than neighboring areas. Spatial autoregressive models assessed the influence of sociodemographic factors on spatial dependencies.

Across 109 health regions, 492 560 individuals were included, representing 29 846 350 Canadians. Crohn's disease and ulcerative colitis were reported in 0.38% and 0.47% of Canadians, respectively. Age and sex-standardized prevalence ranged from 742 to 1267 per 100 000. Significant dependencies among health regions were found, but dependencies were explained by the distribution of sociodemographic characteristics in a region.

Results demonstrated significant geographic variations in the prevalence of IBD in Canada. Evidence suggests that differences in prevalence between regions are primarily driven by individual demographics rather than geographical characteristics.