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

This study analyzed inflammatory bowel disease activity for 2 years after the Great East Japan Earthquake.

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.

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.

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.