During recent several years, the incidence of ulcerative colitis is rapidly increasing in Korea. Both patients and physicians await good predictors of individual clinical course in terms of morbidity. We wanted to analyse not only clinical features in ulcerative colitis at the time of diagnosis, but also clinical courses during 5 years after diagnosis. Factors affecting clinical courses were also investigated.
Methods One hundred and seventy‐four patients with ulcerative colitis regularly followed at least 1 year, spanning from January 1988 to October 2000, were included. Morbidity was evaluated using annual disease burden index, defined as summation of monthly clinical severity (0 for remission, 1 for mild, 2 for moderate, and 3 for severe). Multiple variables such as, demographic parameters, social history, symptoms, duration before diagnosis, extent of disease, endoscopic as well as clinical severity, laboratory data including ANCA and treatment, were used to identify factors affecting clinical course.
Results Mean annual disease burden index at first, third and fifth year after diagnosis was 5.8 ± 4.4, 4.9 ± 5.3, and 3.8 ± 4.1, respectively. Mean annual symptomatic period also decreased from 4.0 ± 3.1 months at first year to 3.0 ± 3.4 months in fifth year. Presence of fever at the time of diagnosis was the only factor affecting annual disease burden index and symptomatic period at first year after diagnosis. Cumulative relapse free at 1, 2, and 5 years after diagnosis were 58.2, 68.2 and 86.8%, respectively. Young age at onset (< 30), short extent of disease (proctitis and left‐sided colitis vs. extensive colitis), and history of transfusion were factors significantly related with higher relapse rate (P < 0.05, log–rank test).
Conclusion Disease burden index and symptomatic period in each year tend to decrease with time during 5 years after diagnosis. Cumulative relapse rate in Korean patients with ulcerative colitis was comparable to that in Western countries and was affected by age at onset, extent of disease, and history of transfusion.