Maastricht University Medical Centre and Ferring.

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.

EO IBD is rising, warranting physicians' alertness for IBD in elderly patients. The long-term outcome was not different from AO disease, despite a less frequent use of immunomodulators and biologicals.

Screening for variants in TPMT did not reduce the proportions of patients with hematologic ADRs during thiopurine treatment for IBD. However, there was a 10-fold reduction in hematologic ADRs among variant carriers who were identified and received a dose reduction, compared with variant carriers who did not, without differences in treatment efficacy. ClinicalTrials.gov number: NCT00521950.

Between 1991 and 2014, the hospitalization and surgery rates decreased, whereas progression to complicated disease is still common in CD. These improvements were not significantly related to the use of immunomodulators and biologicals.