THE LYON SCORE: A NOVEL REFLUX SCORING SYSTEM BASED ON THE LYON CONSENSUS 2.0 THAT ASSOCIATES WITH TREATMENT OUTCOME FROM ANTI-REFLUX THERAPY

Background: We explored if a score derived from parameters from esophageal testing could increase confidence in diagnosing conclusive gastroesophageal reflux disease and in predicting outcome. Methods: A prediction score was developed using metrics based on Lyon Consensus 2.0 thresholds extracted from endoscopy and pH-impedance monitoring. The Lyon score was the sum of weighted scores derived from a logistic regression model. The outcome was response to anti-reflux therapy, defined as 50% reduction in global symptoms on validated questionnaires. An existing database of endoscopy-negative patients with typical reflux symptoms undergoing esophageal testing from two centers (Europe and US) constituted the developmental cohort, while two separate cohorts (Europe and Asia) served as validation cohorts. Receiver operating characteristics (ROC) analysis determined performance of the Lyon score in predicting treatment response. Results: In 281 developmental cohort patients (median age 53 years, 57.7% female), the Lyon score demonstrated an AUC of 0.819 in predicting 50% symptom improvement (p<0.001) on ROC, with an optimal threshold of 6.25 (sensitivity 81.2%, specificity 73.4%). Of the individual components, only acid exposure time (AUC 0.799, p<0.001), mean nocturnal baseline impedance (AUC 0.785, p<0.001) and reflux episodes (AUC 0.764, p<0.001) approached the Lyon score performance. The Lyon score segregated treatment response in both the European (AUC 0.908, p<0.001) and Asian validation cohorts (AUC 0.637, p<0.001), and outperformed the DeMeester score in sensitivity for predicting outcome in the developmental and Asian validation cohorts. Conclusion: The novel Lyon score segregates reflux phenotypes, and identifies likelihood of symptom response from antireflux therapy.