Health Care Cost Analysis in a Population-based Inception Cohort of Inflammatory Bowel Disease Patients in the First Year of Diagnosis

Background: There are limited prospective population-based data on the health care cost of IBD in the post-biologicals era. A prospective registry that included all incident cases of inflammatory bowel disease [IBD] was established to study disease progress and health cost. Aim: To prospectively assess health care costs in the first year of diagnosis among a well-characterised cohort of newly diagnosed IBD patients. Method: Incident cases of IBD were prospectively identified in 2007-2008 and 2010-2013 from multiple health care providers, and enrolled into the population-based registry. Health care resource utilisation for each patient was collected through active surveillance of case notes and investigations including specialist visits, diagnostic tests, medications, medical hospitalisation, and surgery. Results: Off 276 incident cases of IBD, 252 [91%] were recruited to the registry, and health care cost was calculated for 242 (146 Crohn's disease [CD] and 96 ulcerative colitis [UC] patients). The median cost in CD was higher at A$5905 per patient (interquartile range [IQR]: A$1571-$91,324) than in UC at A$4752 [IQR: A$1488-A$58,072]. In CD, outpatient resources made up 55% of all cost, with medications accounting for 32% of total cost [15% aminosalicylates, 15% biological therapy], followed by surgery [31%], and diagnostic testing [21%]. In UC, medications accounted for 39% of total cost [of which 37% was due to 5-aminosalicylates, and diagnostics 29%; outpatient cost contributed 71% to total cost. Conclusion: In the first year of diagnosis, outpatient resources account for the majority of cost in both CD and UC. Medications are the main cost driver in IBD.