P693 Inflammatory bowel disease in Norway 1999 to 2014: increasing prevalence and local geographical differences
M. L. Hoivik*1, B. Moum2, T. Glomsaker3
1Oslo University Hospital, Department of Gastroenterology, Oslo, Norway, 2Oslo University Hospital, Department of Gastroenterology, Oslo, Norway, 3Oslo University Hospital, Department of Surgery, Oslo, Norway
An increasing occurrence of inflammatory bowel disease (IBD) and geographical differences have been reported worldwide the last decades. In Norway, no national prevalence figures have been published. The aim of this study was to determine the time trends in prevalence of ulcerative colitis (UC) and Crohn’s disease (CD) in Norway by exploring data from the Norwegian Patient Registry (NPR).
Data were retrieved from the NPR, which includes all patient contacts in the specialist health care services from 1999 through 2014. IBD cases were defined as persons with records of the ICD-10 codes K 50 or K51 in the registry during 1 year. Overall number of IBD cases were reported as per year and stratified by diagnosis, gender, age, and county. The corresponding population figures were retrieved from Statistics Norway and used to calculate prevalence with 95% confidence intervals.
The national prevalence of CD increased from 88 (85 to 91) / 100.000 in 1999 to 185 (181 to 189) / 100.000 in 2014 (110% increase). Corresponding UC prevalence was 139 (136 to 142) / 100.000 in 1999 and 250 (245 to 254) / 100.00 in 2014 (80% increase). Men had the highest UC prevalence throughout the observation period with a male/female ratio of 1.23 in 1999 and 1.09 in 2014.There was no gender difference in CD prevalence in 1999 (male/female ratio 1.0). The CD prevalence in women increased more than in men during the observational period and by 2014 the male/female ratio for CD prevalence was 0.86. As from 2002 and onwards, CD prevalence was significantly higher than UC prevalence in the age groups 0 to 19 years (2002 CD prevalence; 37 [33 to 40] / 100.000 vs UC prevalence 29 [26 to 32] /100.000). For all other age groups UC prevalence was higher than CD prevalence throughout the time period. There was a significant difference in prevalence between counties. In 2014 UC prevalence ranged from 181 (162 to 200) / 100.000 (Oppland County) to 385 (352 to 418) / 100.000 (Nord-Trøndelag county) and for CD from 139 (128 to 150) / 100.000 (Rogaland County) to 272 (151 to 293) / 100.000 (Nordland County). The highest prevalence figures were seen in the northern and western parts of the country.
The prevalence of UC and CD has increased significantly the last 15 years. In 2014 UC was more prevalent in men and CD more prevalent in women. From 2002 CD was more prevalent than UC in the age group 0 to 19 years. Striking differences in prevalence between geographical areas were found. Awareness of time trends in IBD occurrence is crucial, and it provides the basis of organisation of health care services for this patient group.