Objective The introduction of anti tumour necrosis factor-α (anti-TNFα) therapy might impact healthcare expenditures, but there are limited data regarding the costs of inflammatory bowel diseases (IBD) following the introduction of these drugs. We aimed to assess the healthcare costs and productivity losses in a large cohort of IBD patients.

Design Crohn's disease (CD) and ulcerative colitis (UC) patients from seven university hospitals and seven general hospitals were invited to fill-out a web-based questionnaire. Cost items were derived from a 3 month follow-up questionnaire and categorised in outpatient clinic, diagnostics, medication, surgery and hospitalisation. Productivity losses included sick leave of paid and unpaid work. Costs were expressed as mean 3-month costs per patients with a 95% CI obtained using non-parametric bootstrapping.

Results A total of 1315 CD patients and 937 UC patients were included. Healthcare costs were almost three times higher in CD as compared with UC, €1625 (95% CI €1476 to €1775) versus €595 (95% CI €505 to €685), respectively (p<0.01). Anti-TNFα use was the main costs driver, accounting for 64% and 31% of the total cost in CD and UC. Hospitalisation and surgery together accounted for 19% and <1% of the healthcare costs in CD and 23% and 1% in UC, respectively. Productivity losses accounted for 16% and 39% of the total costs in CD and UC.

Conclusions We showed that healthcare costs are mainly driven by medication costs, most importantly by anti-TNFα therapy. Hospitalisation and surgery accounted only for a minor part of the healthcare costs.