Clinical validation and accuracy assessment of the Capsule Endoscopy-Crohn's Disease index (CE-CD).

Objectives: To compare the recently proposed Capsule Endoscopy-Crohn's Disease index (CE-CD) to pre-existing capsule endoscopy (CE) scores, to measure its precision and accuracy to predict adverse clinical outcomes in children with Crohn's disease (CD).

Methods: Children with CD who underwent CE at diagnosis and had, at least, 1-year follow-up postprocedure were selected. Capsule study was viewed and the different indices were independently scored by two trained paediatric gastroenterologists. The relationship between pre-existing scores and CE-CD was assessed by linear regression analysis. Clinical outcomes prediction assessment was based on receiver operating characteristics curves, survival analysis and Cox regression. Finally, interobserver agreement was measured.

Results: Fifty-nine patients were finally included. CE-CD showed a strong positive correlation with the Lewis score (ρ = 0.947) and the Capsule Endoscopy Crohn's Disease Activity Index (CECDAI) (ρ = 0.982). Both CE-CD and CECDAI were significant predictors of treatment escalation (hazard ratio 1.07 and 1.09, respectively, with both p-values < 0.01). However, no score predicted risk of hospital admission, surgery or clinical/endoscopic relapse. The presence of moderate-to-severe small bowel (SB) inflammation, defined as a score of ≥9 on CE-CD, provided a hazard ratio of treatment escalation of 2.6 (95% confidence interval: 1.3-5.3). This cut-off provided the optimal sensitivity/specificity pair: 48.4%/89.3%. No interobserver misclassification among inflammation categories given by CE-CD were observed (kappa 100%).

Conclusion: CE-CD is a useful tool to document SB inflammation in children with CD. It correlates strongly with classical scores, can better predict need for treatment escalation and shows good interobserver agreement.