Long-term Prognosis of Crohn's Disease and Its Temporal Change Between 1981 and 2012: A Hospital-based Cohort Study from Korea

Background: To date, no large-scale studies have evaluated the prognosis of Crohn's disease (CD) over a period of 3 decades in non-Caucasian populations. The aims of this study were to update the current information on the long-term prognosis of CD using a large series of patients and to evaluate changes in treatment paradigms over time and their impact on the prognosis of CD in Korea. Methods: We retrospectively analyzed 2043 Korean patients with CD who visited the Asan Medical Center. The study subjects were divided into 3 groups according to the year of diagnosis (cohort 1: 1981-2000, cohort 2: 2001-2005, and cohort 3: 2006-2012). Results: Azathioprine/6-mercaptopurine and anti-tumor necrosis factor agents have been used increasingly more frequently and earlier over the past 30 years, with a 5-year cumulative probability of prescription of 28.9% and 1.4%, respectively, in cohort 1 and 88.1% and 23.7%, respectively, in cohort 3 (P < 0.001). A total of 726 patients (35.5%) underwent intestinal resection, with a cumulative probability of intestinal resection 10, 20, and 30 years after diagnosis of 43.5%, 70.0%, and 76.1%, respectively. The cumulative probability of surgery was significantly lower in cohort 3 than in cohort 1 (P = 0.012). Early use of azathioprine/6-mercaptopurine was significantly associated with delayed need for intestinal resection by multivariate Cox analysis (hazard ratio: 0.63, 95% confidence interval: 0.46-0.85). Conclusions: Korean patients with CD may have a similar clinical course to Westerners, as indicated by the intestinal resection rate. The surgery rate has decreased over time, and early use of azathioprine/6-mercaptopurine was related to its decrease.