Long-term follow-up study of Crohn's disease in Japan. The Research Committee of Inflammatory Bowel Disease in Japan.

Two hundred and three patients with Crohn's disease seen at Kyushu University, Fukuoka University, and their affiliated centers from 1973 to 1988 were followed for 4.4 +/- 3.2 years (mean +/- SD), to evaluate the prognosis relative to life span and surgery. Cumulative survival rate and cumulative operation rate were calculated by the life table method. Cumulative survival rates 5 and 10 years after diagnosis were 98.9% and 98.9%, respectively; these figures were not different from the expected survival rates in the sex-and age-matched general population. Cumulative operation rates 5 and 10 years after the onset of symptoms were 16.2% and 39.1%, respectively, In a second study, we investigated 419 patients with Crohn's disease, diagnosed at nine institutions from 1975 to 1990. The follow-up period was 6.3 +/- 3.9 years and the information was obtained from mailed questionnaires. Cumulative survival rates 5 and 10 years after diagnosis were 99.2% and 96.9%, respectively. Cumulative operation rates 5 and 10 years after the onset of symptoms were 30.3% and 70.8%, respectively. These results indicate that the prognosis of Japanese patients with Crohn's disease may be superior to that reported in Western countries.