IBD Disability Index Is Associated With Both Direct and Indirect Costs of Inflammatory Bowel Disease

Introduction: We aimed to determine both direct (medical) and indirect (lost wages) costs of IBD and the association between the degree of IBD-related disability and extent of IBD-related costs. Methods: Persons age 18-65 from the population-based University of Manitoba IBD Research Registry completed a survey including the IBD Disability Index (IBDDI) and questions related to employment, missed work (absenteeism), and reduced productivity at work (presenteeism). Administrative health data including surgeries, hospitalizations, physician claims, and prescriptions were linked to the survey and assessed. To calculate annual wage loss, number of days of missed work was multiplied by the average wage in Manitoba for the given occupation per Statistics Canada. Costs were adjusted to 2016-17 Canadian dollars. Using descriptive and regression analysis, we explored the association between IBDDI and annual direct and indirect costs associated with IBD. Results: Average annual medical costs rose from $1918 among those with IBDDI 0-4 to $9,993 among those with IBDDI 80-86. Average annual cost of lost work rose from $0 among those with IBDDI 0-4 to $30,101 among those with IBDDI 80-86. Using linear regression, each additional unit of IBDDI was associated with an increase of $77 in annual medical cost (95% CI, $52-102; P < .001) and an increase of $341 in annual cost of lost wages (95% CI, $288-395; P < .001). Conclusions: Costs related to IBD are significantly associated with the degree of IBD-related disability. Among the approximate 30% of the IBD population with IBDDI scores >= 40, the indirect costs of absenteeism and presenteeism accounts for similar to 75% of the total IBD-related costs.