An endoscopic scoring system for achalasia: the CARS score

Background and Aims: The diagnosis of achalasia is associated with an average delay of 2 years. Endoscopic features may prompt an earlier diagnosis. We aimed to develop and test a novel endoscopic score, CARS, 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 4 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 4 components: Contents, Anatomy, Resistance, and Stasis. In a mixed-effects model, the mean score across raters was higher for achalasia compared with nonachalasia subjects (4.44 vs 0.87; P < .01). In part 2 of the study, achalasia patients had a higher mean CARS score compared with those with no or ineffective motility disorder (mean 4.1 vs 1.3; P < .01). Conclusions: We developed a CARS score based on reliability performance in a video-based survey and tested the score in a clinical setting. The CARS score performed well in predicting achalasia.