Crohn's disease in Norway 1956-63.

EDITORIAL COMMENT The incidence of Crohn's disease in Norway has been studied for the eight-year period 1956-63. A total of 73 cases of typical Crohn's disease was reported. The average annual rate per 1,000,000 population was 2-6 and the incidence during the period under review may have risen. There was no sex difference. The incidence was low in the youngest age groups. The rate did not vary with geographical area. The ratio for the incidence of ulcerative colitis to Crohn's disease for the period was 9-3:1. The incidence of ulcerative colitis in Norway has been studied by Ustvedt (1958) for the 10-year period 1946-55 and by Gjone and Myren (1964) for the five-year period 1956-60. All paediatric and medical departments of the country and the majority of small mixed hospitals gave individual information on their cases. For the last five-year period a total of 362 typical cases of ulcerative colitis was reported and the average annual rate per 1,000,000 population was 20-6, a rise in incidence from previous five-year periods. The incidence of Crohn's disease in Norway has now been studied in a similar way for the five-year period 1956-60 and also for the years 1961-63. The results of this study are presented here and a comparison of the incidence of Crohn's disease and of ulcerative colitis is also given. PRESENT INVESTIGATION Personal letters were sent to the heads of all the paediatric, medical, and surgical departments of the country and also to the heads of all the mixed hospitals. We asked for individual reports on all patients who had been treated for Crohn's disease in the years 1956-63. Crohn's disease was defined as a chronic relapsing enteritis of unknown aetiology which usually affects the distal ileum but may also affect the colon, presenting symptoms of intestinal stenosis, diarrhoea, anaemia, and fistula. Standardized report forms were sent to all departments. We asked for a report on all cases which had been given the diagnosis of regional enteritis, terminal enteritis, terminal ileitis, or Crohn's disease, requesting on the individual information forms the patient's name, sex, date of birth, address. date of first admission for Crohn's disease in 1956-60, the year of first diagnosis, and the hospital's own evaluation of the case with registration as typical Crohn's disease or not. We also asked for comments from the reporting physician on the correct-ness of the diagnosis. If the diagnosis did not seem to …