(P-377) Users of Biologics for Crohn’s Disease and Ulcerative Colitis in the Netherlands

Background: Since 2017, a new database is available in the Netherlands, DHD-Addon Database, documenting the use of drugs, mostly biologicals, categorised as expensive drugs prescribed exclusively by medical specialists and distributed by specialised pharmacies located in hospitals.

Objectives: To compare patient characteristics of patients with Crohn’s disease (CD) or ulcerative colitis (UC) using biologics from the DHD-Addon Database with patients with CD or UC using biologics from the PHARMO GP Database, thereby exploring the validity of the DHD-Addon Database.

Methods: Patients with an indication of CD or UC for a biologic dispensing between 2017 and 2019 were selected from the DHD-Addon Database, as part of the PHARMO Database Network (HRX cohort). Another group of patients with a diagnosis of CD or UC as recorded by their general practitioner (GP) between 2010 and 2019 were selected from the GP Database, and were linked to Out-patient Pharmacy Database to capture biologic use (GRX cohort). The index dates in both cohorts were defined as the date of use of the first biologic. Patients aged ≥ 18 years were required to have at least 6 months of continuous medical history prior to index date. Biologic-naïve patients were defined as patients who were not treated with a biologic during their available data history. Patients treated with a biologic during their available data history were considered to be biologic-experienced. Patient characteristics (age, sex and type of biologic) at index date in each cohort were assessed.

Results: In the HRX cohort, 3,664 patients with an indication of CD (median age 39 years; 59% women) and 1,328 patients with UC (median age 47 years; 46% women) were identified. Of the CD and UC patients, 65% and 51% were biologic-experienced, respectively. Among the CD and UC patients treated with biologics, infliximab and adalimumab were mostly used.
In the GRX cohort, 5,066 patients with CD and 5,475 patients with UC were identified. Of these patients, only in 2%, a dispensing of biologics was found. Among those patients using biologics, 189 (97%) patients with CD (median age 38 years; 59% women) and 64 (98%) patients with UC (median age 48 years; 45% women) were biologic-naïve. These CD and UC patients treated with biologics used predominantly adalimumab.

Conclusions: Patient characteristics were similar between the HRX and GRX cohort. Given the limited size of the study population with linked data from the Out-patient Pharmacy Database and the GP Database, the number of patients with CD or UC was too small to study the use of biologics. We recommend to study the use of biologics among patients with CD or UC in the DHD-Addon Database.