METHODS: A population of 295 consecutive patients undergoing HRM and pH-study for persistent typical or atypical GERD symptoms was prospectively enrolled to build a model and a nomogram that provides a risk score for AET > 6%. Collected HRM data included IEM, EGJ-CI, EGJ type and SLR. A supplemental cohort of patients undergoing HRM and pH-study was also prospectively enrolled in 13 high-volume esophageal function laboratories across the world in order to validate the model. Discrimination and calibration were used to assess model's accuracy. Gastroesophageal reflux disease was defined as acid exposure time >6%.

RESULTS: Out of the analyzed variables, SLR response and EGJ subtype 3 had the highest impact on the score (odd ratio 18.20 and 3.87, respectively). The external validation cohort consisted of 233 patients. In the validation model, the corrected Harrel c-index was 0.90. The model-fitting optimism adjusted calibration slope was 0.93 and the integrated calibration index was 0.07, indicating good calibration.

CONCLUSIONS: A novel HRM score for GERD diagnosis has been created and validated. The MS might be a useful screening tool to stratify the risk and the severity of GERD, allowing a more comprehensive pathophysiologic assessment of the anti-reflux barrier.

METHODS: 535 patients with suspected GERD who underwent HRM and reflux monitoring were retrospectively analyzed. Clinical, HRM, and reflux study data were compared between the EGJ morphology subtypes, with objective GERD defined according to Lyon Consensus 2.0. The Milan Score, a novel metric that integrates ineffective esophageal motility, EGJ-contractile integral, EGJ morphology, and straight leg raise response, was abnormal when ≥ 137 (risk rate 50% for GERD). Receiver operating characteristic (ROC) curve analysis was performed to assess the accuracy of the Milan Score to predict objective GERD.