Validation of the ASALT Score for Predicting Biliary Etiology in Acute Pancreatitis: a Single-Center Study of 441...

Early identification of biliary etiology in acute pancreatitis (AP) is essential because it directly influences therapeutic decisions and secondary prevention. However, determining biliary origin in the early phase remains challenging, especially when initial ultrasonography is inconclusive. The ASALT score, based on age, sex and alanine aminotransferase (ALT), was previously proposed as a simple bedside tool for predicting biliary etiology.

To evaluate the performance of the ASALT score in a larger cohort of patients with acute pancreatitis and to externally validate its diagnostic accuracy for predicting biliary etiology.

We performed a retrospective study including 441 patients admitted with acute pancreatitis between January 2014 and December 2024. Biliary etiology was established by serial abdominal ultrasonography, endoscopic ultrasonography, or magnetic resonance imaging. Independent predictors were evaluated by multivariable logistic regression. Discriminative ability of the ASALT score was assessed by receiver operating characteristic analysis.

A total of 436 patients (56.5% males) with a median age of 60 years (range 18-95) were included. Biliary etiology was most frequently found (60.1%) and it was associated with the highest median age (65 years), followed by alcohol (22.5%). Biliary pancreatitis predominated in females (60.7%), while non-biliary etiologies showed a marked male predominance. A history of acute pancreatitis significantly differentiated biliary from non-biliary causes (χ²=39.7, p<0.001). Multivariable binary logistic regression identified age (p < 0.001), sex (p < 0.001) and ALT (p = 0.002) as variables independently associated with biliary etiology. The ASALT score demonstrated good discrimination [area under the curve (AUC)=0.820, 95% confidence interval (CI) 0.777-0.862, p<0.0001)], with an optimal cutoff of 1, yielding 77.6% accuracy and 69% negative predictive value. Each 1-point increase in ASALT score tripled the odds of biliary etiology (p<0.001).

The ASALT score is a simple and practical tool with good diagnostic performance for early prediction of biliary etiology in acute pancreatitis, which is particularly useful when access to advanced imaging is limited.