Depression and anxiety are associated with poor outcomes in patients with inflammatory bowel disease: A nationwide population-based cohort study in South Korea

Background: Prevalence of depression and anxiety are known to be increased in patients with inflammatory bowel disease (IBD), but it is unclear whether such elevations adversely affect IBD outcomes. Objective: We aimed to investigate the association between depression or anxiety and clinical outcomes of IBD. Method: Using claims data from the South Korean National Health Insurance Service (NHIS), patients with IBD were identified by codes of the International Classification of Disease, 10th Revision (ICD-10) and the Rare/ Intractable Disease (RID) registration program for years 2010 to 2017. ICD-10 codes were also used to identify depression and anxiety in this population. Primary study endpoints were IBD-related outcomes, including emergency room (ER) visits, hospitalizations, and surgeries during the follow-up period. Results: Our cohort included 32,867 patients with IBD, of whom 3794 (11.5%) experienced depression and anxiety during the 6-year median follow-up period. In multivariate analysis, comorbid depression and anxiety were associated with increased risks of ER visits (hazard ratio [HR] = 1.34, 95% confidence interval [CI]: 1.19-1.51) and hospitalizations (HR = 1.24, 95% CI: 1.12-1.37), whereas surgical risk was not different for IBD patients with and without depression and anxiety. There was no differential effect of depression and anxiety on outcomes in IBD patients, but depression was more closely associated with outcomes in CD patients and anxiety in UC patients. Conclusion: In patients with IBD, comorbid depression and anxiety are associated with increased risks of ER visits and hospitalizations, but not surgery. These associations are more pronounced for depression in CD patients and for anxiety in UC patients.