External validation of a Capsule Endoscopy Scoring System (CESS-CD) for early Crohn's disease diagnosis

Small bowel capsule endoscopy (SBCE) is widely recognized as a key diagnostic tool for Crohn's disease (CD). While several scores assess disease activity, a validated scoring system specifically designed for diagnosis was lacking. The Capsule Endoscopy Scoring System for Crohn's Disease (CESS-CD) was introduced in 2025 to address this gap in early CD diagnosis.

To externally validate the diagnostic performance and clinical utility of the CESS-CD in an independent, single-center cohort, clinical and SBCE data from 135 patients were retrospectively analyzed. The CESS-CD score was calculated based on age ≤30 years (3 points), presence of linear erosion (4 points), and circumferential alignment (4 points). Final diagnosis of CD was established by experienced gastroenterologists. Diagnostic performance was assessed via ROC curve analysis, with accuracy metrics calculated at the predefined cut-off of ≥7 points. Group differences were evaluated using the Mann-Whitney U test.

The CESS-CD showed excellent diagnostic discrimination, with an AUC of 0.973 (vs. 0.925 in the original study). At the 7-point cut-off, sensitivity was 96.8% (vs. 83.3%), specificity 90.4% (vs. 80.0%), PPV 75.0% (vs. 83.3%), NPV 98.9% (vs. 80.0%), and overall accuracy 91.9%. CESS-CD scores were significantly higher in patients with CD compared to those without (p < 0.001).

This external validation confirms the CESS-CD as a highly accurate and robust diagnostic tool for early CD. Its strong sensitivity, NPV, and discriminative ability support its integration into clinical practice to enhance diagnostic precision and guide timely management.