Introduction: Inflammatory bowel disease (IBD) is very disabling condition. Due to the chronic nature of IBDs, it is crucial to better understand the economic burden in a real-world setting. Methods: We conducted a retrospective descriptive study using the health information systems of the Agency for Health Protection of the Province of Milan (3.5 million inhabitants) for the period 2011-2015. Average cost per patient was calculated for each disease (ulcerative colitis and Crohn's disease). Subgroup analyses were performed regarding patients treated with biologics.A generalized linear model controlling for patient age and Charlson co-morbidity index was used to calculate the adjusted mean costs. Regression analyses were based on dependent variables of individual costs. Results: A total of 12,720 IBD cases were studied, 7,981 of ulcerative colitis (UC) and 4,739 of Crohn's disease (CD). The mean total cost of UC patients was €12,707 and €9,527 for CD patients (euro 2017). The mean total cost of UC patients treated with infliximab was higher compared to patients treated with adalimumab, €16,124 vs. €15,174; conversely, the costs were higher for CD patients treated with adalimumab (€14,440 vs. €13,770). In the total for patients with IBD who were treated with biologics, only duration of disease and comorbidities were significantly correlated with costs.
Discussion and Conclusion:In this large population-level study in Italy, we estimated all direct medical costs for IBD patients. This cost-of-illness study offers insight into resource utilization and particularly into the use of biologics treatments.