A Simple Risk Score to Predict the Likelihood of a Positive Endoscopic Ultrasound in Idiopathic Acute Pancreatitis.

BACKGROUND & AIMS: We sought to derive a risk score, DORM65, of known variables to predict the likelihood of a positive EUS in patients with idiopathic acute pancreatitis (IAP).

METHODS: A retrospective cohort study of 180 patients with IAP was performed across three tertiary care centers between January 2018 and December 2021. Multivariate logistic regression modeling was performed to predict a positive EUS. Accuracy of the models were assessed by the area under the receiver operating characteristic curve (AUROCC).

RESULTS: The diagnostic yield of EUS was 58.9% (95% CI, 51.7-66.1%). The DORM65 score of 5 predictors present before EUS with the best discrimination were a delayed EUS (defined as ≥ 82 days from the last episode of acute pancreatitis), obesity, not having had a repeated transabdominal ultrasound, being male, and age ≥ 65 years at time of EUS. For those at the lowest risk score group, the positive EUS rate was 13.0% compared with 100% in those at the highest risk group, (relative risk [RR] 7.67, p <0.001). A score of 3 or more had a positive predictive value of 86.0% with a sensitivity of 34.9% and specificity of 91.9%. The model had a high predictive accuracy (AUROCC = 0.774; 95% CI, 0.707-0.841). Adding 3 additional predictors (no cholecystectomy, no magnetic resonance cholangiopancreatography [MRCP], and having a single episode of acute pancreatitis) did not increase the accuracy significantly (AUROCC = 0.805; 95% CI, 0.742-0.867).

CONCLUSION: DORM65 is easily calculated and accurately predicts a positive EUS in patients with IAP. Further validation is needed.