Long-term evolution of direct healthcare costs for inflammatory bowel diseases: a population-based study (2006-2015)

Introduction: We explored the long-term evolution of direct healthcare costs for inflammatory bowel diseases (IBD) using a population-level database in a country with an escalating burden of IBD. Methods: We searched the database of the Korean National Health Insurance Claims, which covers more than 97% of the South Korean population. An IBD diagnosis was defined as the combination of a billing code for Crohn's disease (CD: K50.xx) or ulcerative colitis (UC: K51.xx) and at least one claim for IBD-specific drugs. Between 2006 and 2015, a total of 59,447 patients (CD: 17,677; UC: 41,770) were included. Results: The total and mean cost per capita increased significantly over time. In the last year of the study (2015), the cost for anti-tumor necrosis factor (TNF) therapy accounted for 68.8% (CD) and 48.8% (UC) of the total cost. Age at diagnosis (<20 years vs. >= 30 years) and anti-TNF use were independent predictors of increased total IBD cost. Anti-TNF therapy was the strongest predictor of high-cost outliers (designated as the top 20 percentile of the total costs) for IBD (OR: 160.4; 95% CI: 89.0-289.2). The mean cost among patients with newly diagnosed CD increased significantly over the 8-year follow-up period (p = .03), while costs associated with UC remained stable. Only medication costs increased significantly during the follow-up period for CD. Conclusions: Over the past 10 years, the increased usage of anti-TNF agents has been the key driver of IBD-related healthcare costs. Long-term cost-cutting strategies for patients with CD are warranted.