Development of a capsule endoscopy scoring system for the early diagnosis of small bowel Crohn's disease.

Background: Small bowel capsule endoscopy (SBCE) is a reliable method of evaluating small bowel mucosal lesions, and its use in Crohn's disease (CD) is increasing. We previously reported useful SBCE findings for early diagnosis of CD. In the present study, we developed a scoring model for early diagnosis of CD using SBCE findings.

Methods: We collected clinical and SBCE data of 110 patients with small bowel mucosal lesions and randomly divided them into derivation and validation cohorts. After selecting variables for scoring models by univariate analysis, the adopted model was determined. The score of each variable was based on the odds ratio obtained by multivariate analysis, and the cut-off value for the diagnosis of CD was examined by receiver operating characteristic analysis. Its reliability was verified in the validation cohort.

Results: The model containing age (≤ 30 vs. ≥ 31), linear erosion, and circumferential alignment had the best fit (odds ratios of 4.97, 7.56, and 5.34, respectively). The linear erosion score was defined as 4 points, circumferential alignment as 4, and age of ≤ 30 years as 3. When the cut-off value was defined as 7 points, the scoring model had 85.4% sensitivity, 80.0% specificity, 83.7% positive predictive value, and 82.1% negative predictive value for diagnosis of CD. The validation cohort demonstrated an area under the curve of 0.93, similar to the derivation cohort.

Conclusion: We developed a scoring model for early diagnosis of CD based on SBCE findings, possibly contributing to the improvement of the long-term outcome of CD.