Comparing Three Scoring Models for Predicting Unruptured Intracranial Aneurysm Progression in Subarachnoid Hemorrhage Patients with Multiple Intracranial Aneurysms.

RATIONALE AND OBJECTIVES: Accurate assessment of unruptured intracranial aneurysm (UIA) progression risk is essential in aneurysmal subarachnoid hemorrhage patients with multiple intracranial aneurysms (aSAH-MIA patients), and the PHASES (population, hypertension, age, size, earlier SAH, site), ELAPSS (earlier SAH, location, age, population, size, shape), and Juvela's score are available for such risk prediction. We aimed to compare their predictive efficacy for UIA progression in this cohort. MATERIALS AND METHODS: This retrospective study enrolled 319 aSAH-MIA patients from September 2011 to August 2025. Cox regression models with cluster-robust standard errors, C-index, Brier score, and decision curve analysis were adopted to assess the discrimination, calibration, and clinical utility of different scoring systems. RESULTS: The ELAPSS and PHASES scores were significantly associated with UIA progression in aSAH-MIA patients, before and after adjustment for confounders, whereas Juvela's score was not. Comprehensive comparison of predictive performance demonstrated that the ELAPSS score achieved the best overall performance (C-index 0.781; 60-month area under the curve [AUC] 0.865) with lower Brier scores than the PHASES score, followed by the PHASES score (C-index 0.719; 60-month AUC 0.847); the Juvela's score exhibited the worst performance (C-index 0.530; 60-month AUC 0.456) and lacked predictive power in the present cohort. CONCLUSION: Both the ELAPSS and PHASES scores can independently predict UIA progression, but the ELAPSS score achieves superior predictive performance and is better suited for aSAH-MIA patients. Juvela's score, by contrast, showed no predictive power in this cohort. Overall, the ELAPSS score enables risk stratification and facilitates individualized clinical decision-making.