An endoscopic scoring system for achalasia: the CARS score

Background and Aims The diagnosis of achalasia is associated with an average delay of two years. Endoscopic features may prompt an earlier diagnosis. We aimed to develop and test a novel endoscopic CARS score for the prediction of achalasia. Methods Part 1: Twenty endoscopic videos were taken from patients undergoing endoscopy for dysphagia or reflux. A survey with videos and endoscopic criteria options was distributed to 6 esophagologists and 6 general gastroenterologists. Inter-rater reliability (IRR) was measured and logistic regression was used to evaluate predictive performance. Three rounds of review were conducted to select the final score of four components. Part 2 A retrospective review was conducted for consecutive patients who had comprehensive esophageal testing. Each patient had a CARS endoscopic score calculated based on findings reported at endoscopy. Results From a video review and analysis of score components, IRR ranged from 0.23 to 0.57 for score components. The final CARS score was selected based on the following four components: Contents, Anatomy, Resistance, and Stasis. In a mixed effects model, the mean score across raters was higher for achalasia compared to non-achalasia subjects (4.44 vs. 0.87, p = < 0.01). In part 2 of the study, achalasia patients had a higher mean CARS score compared to those with no / ineffective motility disorder (mean 4.1 vs 1.3, p = < 0.01). Conclusions We developed a CARS score based on reliability performance in a video-based survey and tested the score in clinical setting. The CARS score performed well in predicting achalasia.