The disease severity index for inflammatory bowel disease is associated with psychological symptoms and quality of life, and predicts a more complicated disease course.

Background: The Disease Severity Index (DSI) is a novel tool to predict disease severity in inflammatory bowel disease (IBD). However, its ability to predict disease complications and the presence of psychosocial comorbidity is unclear.
Aims: To assess prospectively associations between the DSI and psychological symptoms, quality-of-life (QoL) and disease outcomes in an IBD cohort.
Methods: Patients with IBD undergoing ileocolonoscopy were followed prospectively for 12 months. DSI, psychological symptoms (perceived stress (PSS-10), depression (PHQ-9), anxiety (GAD-7)) and QoL (IBDQ-32) scores were assessed at baseline. Logistic regression identified variables predicting a complicated IBD course at 12 months (composite outcome of need for escalation of biological/immunomodulator for disease relapse, recurrent corticosteroid use, IBD-related hospitalisation and surgery). Receiver operating characteristics (ROC) analysis identified optimal DSI thresholds predicting a complicated disease course and multivariable logistic regression assessed the risk of reaching this outcome.
Results: One hundred and seventy-two patients were recruited (100 Crohn's disease, 91 female). Median DSI was 21 (IQR 11-32) and 97 patients had endoscopically active disease at baseline. The DSI was significantly higher in patients with symptoms of moderate-severe stress (PSS-10 > 14, p < 0.01), depression (PHQ-9 ≥ 10, p < 0.01), anxiety (GAD-7 ≥ 10, p < 0.05) and impaired quality-of-life (IBDQ-32 < 168, p < 0.01). Only the baseline DSI (OR 1.05, p < 0.01) and endoscopically active disease (OR 6.12, p < 0.01) were associated with a complicated IBD course. A DSI > 23 was strongly predictive of a complicated IBD course (OR 8.31, p < 0.001).
Conclusions: The DSI is associated with psychological distress, impaired QoL and predicts a more complicated disease course in patients with IBD.
(© 2022 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.)