Long-term course of inflammatory bowel disease after the Great East Japan Earthquake.

Background and Aim This study analyzed inflammatory bowel disease activity for 2 years after the Great East Japan Earthquake. Methods We compared the relapse rates of patients with ulcerative colitis or Crohn's disease 1 and 2 years after the earthquake with rates immediately after the earthquake. To evaluate continuous disease courses, we also performed multivariate time-to-event analyses from the time of the earthquake to the onset of additional treatments. Results Of 903 patients with ulcerative colitis or Crohn's disease in our previous study, we could evaluate 2-year courses in 677 patients (394 ulcerative colitis and 283 Crohn's disease). Compared with the relapse rates of ulcerative colitis and Crohn's disease immediately after the earthquake (15.8% and 7.0%, respectively), those in the corresponding periods in 2012 (2.5% and 1.1%, respectively) and 2013 (2.3% and 2.5%, respectively) significantly decreased. There were 226 patients who required additional treatments after the earthquake. Multivariate time-to-event analyses revealed that only patients who had experienced the death of family members or friends were likely to need additional treatments (hazard ratio = 1.77, 95% confidence interval = 1.25-2.47). No other factors had a significant influence. Conclusions The relapse rates 1 and 2 years after the earthquake significantly decreased. The factors that influenced long-term relapse were different from those that influenced short-term relapse.