DOP034 Assessment of direct healthcare cost drivers of Crohn’s disease in a Dutch population-based cohort study shows a major shift

Abstract

Background: Crohn's disease (CD) is associated with substantial direct healthcare costs. Over time, a shift in costs has been observed, from hospitalisation to medication as major cost driver. However, (Figure presented) this observation is based on comparisons of different patient cohorts. Therefore, in this study we aimed to assess shifts in direct costs of CD over the past two decades within the population-based IBD South Limburg (IBDSL) cohort. Methods: All CD patients in the IBDSL cohort with ≥1 year of follow-up were included. Three eras were distinguished based on year of diagnosis: 1991-1998, 1999-1905 and 2006-2011. Patients were followed up to 5 years from diagnosis, till loss-to-follow-up or end of data collection (2014). Data on resource utilisation (i.e. hospitalisation, surgery, diagnostics and medication) were assessed by scrutinising patient files and medical reports. Costs were calculated by multiplying resource use by Dutch reference prices for the corresponding era. If appropriate, prices were corrected for inflation using Dutch consumer price indices. Proportions between eras were compared using Chi-square tests. Results: In total, 1108 CD patients were included. Mean cumulative total costs and breakdown in the major contributing cost elements after 1 and 5 years from diagnosis are presented in Figure 1 for each era. Over time, a decrease in the proportion of hospitalisation costs (p < 0.001), and an increase in the proportion of medication costs (p < 0.001) was observed. The proportion of total costs caused by surgery and diagnostics did not change, although a decrease in absolute surgery costs was observed. The breakdown of medication costs is shown in Figure 2. The proportion of biologicals increased (p < 0.001) and the proportion of mesalamines decreased (p < 0.001) over the eras. No differences were found for steroids or immunomodulators. Five years after diagnosis, biologicals accounted for 4%, 38% and 63% of total costs in era 1991-1998, 1999-2005, and 2006-2011, respectively. Conclusions: This prospective population-based study showed a major shift in cost profiles of CD over the past two decades. Hospitalisation was the major cost driver in the first era (1991-1998), but was replaced by medication in the following eras (1999-2005 and 2006-2011). Nowadays, total costs are mainly driven by biologicals, hence biosimilars may lead to substantial cost reductions.