Abstract
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.