P882 Regional differences in biologic and surgical treatment of inflammatory bowel disease in Norway 2011–2019
Anisdahl, K.(1,2)*;Lirhus, S.S.(3);Medhus, A.W.(1);Moum, B.(2,4);Melberg, H.O.(3,5);Høivik, M.L.(1,2);
(1)Oslo University Hospital, Department of Gastroenterology, Oslo, Norway;(2)University of Oslo, Institute of Clinical Medicine, Oslo, Norway;(3)University of Oslo, Department of Health Management and Health Economics, Oslo, Norway;(4)Østfold Hospital Trust, Department of Gastroenterology, Oslo, Norway;(5)University of Tromsø, Department of Community Medicine, Tromsø, Norway;
We have previously reported regional differences in biologic and surgical treatment for inflammatory bowel disease (IBD) patients diagnosed 2010–2012. In this study, our aim was to explore whether regional differences in the use of biologics and surgery were consistent over time.
We performed a nationwide, observational study using linked data from the Norwegian Patient Registry (NPR) and the Norwegian Prescription Database (Nor-PD). Incident cases were defined as ≥2 IBD diagnosis codes in the NPR, or ≥1 IBD diagnosis code in the NPR and ≥2 IBD prescriptions in the NorPD. Kaplan-Meier estimates were used to calculate time from diagnosis to first biologic and/or major surgical event. The log-rank test was used to test for statistical significance. Patients were stratified by health region affiliation (Northern [NR], Central [CR], Western [WR] and South-Eastern [SER]), and grouped as Cohort I (2011–2014) or Cohort II (2015–2019) depending on year of diagnosis.
We included 7306 patients with Crohn’s disease (CD) and 13688 patients with ulcerative colitis (UC). Results are shown in Figure 1 (CD) and Figure 2 (UC). All cumulative incidences (%) reported below are measured five years after diagnosis.
In Cohort I, SER had the highest (40%) and CR had the lowest (35%) cumulative incidence of patients starting biologics (p=0.02). In Cohort II, WR had the highest cumulative incidence (53%), and differed significantly from NR and SER (p≤0.04).
In Cohort I, there were large regional differences in surgical treatment. NR had lower use of surgery (11%) than all other regions (p≤0.03). In Cohort II, the proportion undergoing surgery had decreased in all regions, except in NR (14%). The use of surgery was lowest in SER (12%), and differed significantly from CR and WR (p≤0.03).
In Cohort I, SER had the highest cumulative incidence of patients starting biologics (18%), and differed significantly from CR and WR (p≤0.01). In Cohort II, the use of biologics was lower in CR (20%) when compared to all other regions (p≤0.01), while differences between the three other regions were non-significant.
CR had the largest proportion of patients undergoing surgery in both Cohort I (8%) and Cohort II (7%), and differed significantly from all other regions in Cohort I (p≤0.05), and SER and WR (p<0.01) in Cohort II. Differences between the three other regions were non-significant.
The study revealed important, sustained regional differences in the use of both biologics and surgery, especially for UC. Pursuing whether geographical treatment variation impacts outcome will aid in ensuring equal access to best clinical care.