Clinical course in Crohn's disease: results of a Norwegian population-based ten-year follow-up study.

BACKGROUND & AIMS: Most studies concerning the clinical course in CD are retrospective or based on selected patient groups. Our aim was to assess the course of CD in a prospective population-based follow-up study and to identify possible prognostic risk factors for complications on the basis of information obtained at initial diagnosis.

METHODS

From 1990-1994, a population-based cohort of 843 new cases of inflammatory bowel disease was recruited in South-Eastern Norway. The cohort was systematically followed up at 1, 5, and 10 years after diagnosis.

RESULTS

Of 237 patients classified as CD, 197 completed the 10 years of follow-up, 18 died, and 22 were lost to follow-up. The cumulative relapse rate during the first 10 years was 90% (95% confidence interval, 86%-94%), and the cumulative probability of surgery was 37.9% (95% confidence interval, 31.4%-44.4%). Terminal ileal location (P < .001), stricturing (P = .004), penetrating behavior (P < .001), and age younger than 40 years (P = .03) at diagnosis were independent risk factors for subsequent surgery. A total of 53% (n = 105) of the patients had developed stricturing or penetrating disease at 10 years. A large proportion of patients (44%) were in clinical remission during the last 5 years of follow-up.

CONCLUSIONS

The prognosis for CD seems better than previously reported. The probability of surgery was low, and fewer than expected developed complicated disease behavior. Nevertheless, the cumulative relapse rate of 90% and the finding of prognostic risk factors for subsequent surgery might call for attention to early effective medical treatment strategies.