Validation of disease severity index for predicting complicated disease in Crohn's disease: A comparison study with Lémann index

BACKGROUND:Disease Severity Index (DSI) provides comprehensive assessment of bowel damage (BD). AIMS:To evaluate DSI in patients with Crohn's disease (CD) at high risk of disease progression, compared to Lémann Index (LI). METHODS:Patients with CD in our center were reviewed consecutively between 2017 and 2019. DSI, LI, and complicated CD course were analyzed. RESULTS:The median LI and DSI of included 300 patients were 1.63 (IQR 1.25-3.13) and 42 (IQR 32-51), respectively. 152 patients (50.7%) experienced a complicated disease course (median 5.1 months; IQR 1.1-20.2). DSI (AUC 0.66; 95% CI 0.60-0.72) better predicted a complicated course of CD over LI (AUC 0.56; 95% CI 0.50-0.63; P = 0.007). The cumulative probability of complicated CD course in severe patients was higher than those with 'mild CD' (P < 0.001). The Cox analysis identified DSI>43 (HR 2.18; 95% CI 1.54-3.09; P < 0.001), B2/3 vs. B1 (HR 2.80; 95% CI 1.99-3.94; P < 0.001), and a higher level of CRP (HR 1.01; 95% CI 1.00-1.02; P = 0.005) as independent prognostic factors for complicated CD. However, LI was not associated with complicated CD (P = 0.164). CONCLUSIONS:Higher DSI was associated with complicated disease outcomes. DSI might play a better role than LI in identifying patients at high risks of disease progression.