Incidence of Inflammatory Bowel Disease in Southeastern Norway: Evaluation of Methods after 1 Year of Registration

Abstract

To assess the feasibility of a prospective incidence study of inflammatory bowel disease (IBD), the registration methods and incidence figures during 1990 were evaluated. The study was a collaboration between 14 hospitals in an area of close to one million inhabitants. Common diagnostic criteria for ulcerative colitis (UC), Crohn’s disease (CD) and indeterminate colitis (IND) were established prior to the start of the study. There was an overall incidence rate for IBD of 19.3 per 10⁵ inhabitants, with 10.6 for UC, 5.1 for CD and 3.6 for IND.The age-specific incidence rates showed a peak between 25 and 34 years for UC and between 15 and 25 for CD. There was a male predominance for UC and a female preponderance for CD. These results are comparable with the previous registrations in western and northern areas of Norway.

Seasonal variations in the onset of ulcerative colitis in Japan

“…We observed monthly seasonality in the symptomatic onset of UC in October and March, mainly in winter and spring. Previous studies have reported seasonal variations in the symptomatic onset of UC in December in the United Kingdom [5,14] , December to January in Norway [15] , and June to August in Spain [16] . Moreover, increased relapse rates for UC were reported in winter [4] and autumn [5] in the United Kingdom, spring to autumn in Greece [8] , and winter in Sweden [7] ; however, other studies reported no seasonality in the United Kingdom [17] , Spain [16] , or the United States [10,18] .…”

Predictive Value of Serologic Markers in a Population-based Norwegian Cohort with Inflammatory Bowel Disease

“…Detailed information concerning the inception cohort is given elsewhere. 19 Prescheduled follow-up visits were carried out at 1, 5, and 10 years after inclusion, at which the diagnosis and disease course was reviewed by the same group of gastroenterologists as in the incidence study. Each visit included a structured interview, clinical examination, and, by patient consent, colonoscopy with biopsies and, if indicated, small bowel enema.…”

What Have We Learnt about the Role of the Environment and Natural Course of IBD in the New Millennium? 20-Year Follow-Up of the IBSEN Cohort

“…The highest incidence rates have been found in Northern and Western Europe and North America [1]. When published in 1996, the incidence numbers from the IBSEN cohort were some of the highest known (13.6/100,000 persons/year for UC and 5.8/100,000 persons/year for CD); thus, the results underlined northern countries being high-incidence areas [2,3,4]. …”