Treatment inferred disease severity in Crohn's disease: evidence for a European gradient of disease course.

Objective: Geographic differences in disease course of Crohn's disease (CD) might possibly be related to differences in genetic and environmental factors encountered in different parts of the world. The aim of this study was to assess differences in treatment regimens within a European cohort of CD patients as a reflection of disease course, and to identify associated phenotypic risk factors at diagnosis.

Material And Methods: A prospective European population-based inception cohort of 380 CD patients was studied. The patients were classified for phenotype according to the Vienna classification. Differences between Northern and Southern European centres in treatment over the first 10 years of disease were analysed using a competing risks survival analysis method.

Results: Patients in the North were more likely to have had surgery (p<0.01), whereas patients in the South were more likely to have been treated medically (p<0.01). Phenotype at diagnosis was not predictive of differences in treatment regimens between North and South.

Conclusions: In this study, a difference in management of CD was observed between Northern and Southern European centres. This suggests that there may be a North-South disease severity gradient across Europe. Phenotypic differences between patients in the North and South did not explain this observed difference.