Addressing real-world data gaps: estimating the uk population cost of crohn's disease and ulcerative colitis using a flexible cost-of-illness model informed by the optimal patient journey and IBDUK patient survey 2023.

backgroundInflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic conditions affecting around 500,000 people in the UK and carries rising prevalence and substantial economic burden. Despite expanding therapeutic choice, contemporary UK cost analyses are scarce. A flexible cost of illness model was developed to estimate the excess costs associated with CDUC in the UK at a population level, including direct NHS costs and societal costs. The model estimates how the direct healthcare and indirect societal costs of IBD change over time, helping to analyse and manage key cost drivers. This supports planning and policy decisions by outlining how interventions and external influences affect long-term spending patterns.

methodsThe study used public data, published research, and the 2023 IBD UK survey to create a cost model covering prevalence, diagnosis, management, complications, and mortality of CD and UC. Clinical management inputs included resource use associated with the ideal pathways in line with IBD Standards. This model estimated and compared healthcare use and complications in people with CD and UC to the general population over 15 years, including costs from flare-ups, remission, and societal impacts.

findingsThe estimated total annual direct healthcare cost based on an optimal patient journey for CD and UC is £3 billion. Ongoing management makes up around 93% of this cost (£2.8 billion), of which 84% of this makes up remission-related treatment in people with active disease. The ongoing management costs of active disease is almost 3 times higher costs in remission, at £185,903,000 and £67,557,000 respectively. The annual lost productivity cost of CD and UC is estimated at around £0.8 billion, mostly due to inability to work. The total healthcare costs are £3.8 billion. In the absence of robust population based real-world data, and given the complexity of IBD care, this model offers a practical solution for estimating population costs, which are likely underestimated, and can be adapted as more accurate datasets become available.

interpretationAlthough pharmacological treatment accounts for a substantial proportion of IBD expenditure, effective control of inflammation and maintenance of remission are likely critical for reducing downstream complications, hospitalisation, surgery, disability, and productivity losses.