Introduction Inflammatory bowel disease (IBD) frequently requires chronic immunosuppressive treatment and active involvement from patients during treatment decision making. Information about the risk of developing adverse drug reactions (ADRs) to IBD therapies is required in this process. Objective The aim of this study was to describe the ADRs reported in IBD patients from real-world data, using the Dutch nationwide IBDREAM registry, and compare the occurrence and cumulative incidences with the Summary of Product Characteristics (SmPC) of the associated drugs. Methods In this retrospective multicentre study, ADRs related to IBD medication were assessed. Only reports associated with the use of drugs used for the maintenance treatment of IBD were included. All ADRs were verified by healthcare professionals and coded by trained pharmacovigilance assessors. Results In total, 3080 ADRs were reported in 1179 patients. Twenty-three new drug–ADR associations related to the use of azathioprine, mercaptopurine, infliximab, oral mesalamine and thioguanine were reported in the IBDREAM registry that were not mentioned in the corresponding SmPCs. The most frequently reported new association was pyrexia for azathioprine (3.1%) and mercaptopurine (4.9%). In addition, there were seven ADRs with a higher cumulative incidence in IBDREAM compared with the SmPC, and included, among others, arthralgia during mercaptopurine use (2.5%), and diarrhoea (1.4%), alopecia (1.2%) and infections (1.6%) during azathioprine use. Conclusions Based on real-world data, ADR reporting demonstrated new ADRs and higher incidences of ADRs to IBD therapies. This information will contribute to drug safety by updating the SmPCs, allowing better risk assessment and communication towards patients. Supplementary Information The online version contains supplementary material available at 10.1007/s40264-021-01045-3.

Purpose To assess the agreement between patient‐reported and health care provider‐reported medical information in inflammatory bowel disease (IBD). Methods This multicentre, prospective, event monitoring study enrolled adult Crohn's disease (CD) and ulcerative colitis (UC) patients treated with a biological in four medical centers in the Netherlands. At two‐monthly intervals, patients completed questionnaires on biological use, combination therapy and indication. The patient‐reported information was compared with their electronic health records (EHRs) and analysed for percentage agreement and Cohen's kappa. A reference population from a prospective IBD registry was used to assess the representativeness of the study population. Results In total, 182 patients (female 50.5%, mean age 42.2 years, CD 76.9%) were included in the analysis. At baseline, 51.0% of the patients were prescribed an immunomodulator (43.9% thiopurines, 7.1% methotrexate), and patients were prescribed biologicals as follows: 59.3% infliximab, 30.2% adalimumab, 9.3% vedolizumab, and 1.1% ustekinumab. Agreement on patient‐reported indication and biological use was almost perfect (κ = 0.878 and κ = 1.000, respectively); substantial for combination therapy (κ = 0.672). Gender, age, type of IBD, biological use and combination therapy were comparable with the reference population. Conclusion Systematic patient‐reporting by questionnaires was reliable in retrieving indication and treatment specific information from IBD patients. These results indicate that the use of patient‐reporting outcomes in daily IBD practice can ensure reliable information collection.