The PHASES score is the validated neurovascular standard for estimating 5-year rupture probability in unruptured asymptomatic aneurysms.
Aneurysm Sentinel Audit
Input all 6 clinical and morphological components to quantify the 5-year rupture risk profile for unruptured intracranial aneurysms.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Evaluating adult patients with incidental or unruptured intracranial aneurysms.
Estimating the 5-year natural history risk of rupture.
Informing clinical decisions regarding surgical clipping or endovascular coiling vs. conservative observation.
Section 2
Literature
Development
The PHASES score was developed by Greving et al. (2014) through a meta-analysis of six prospective cohorts involving over 8,000 patients. It identified six key predictors: Population (ethnicity), Hypertension, Age, Size, Earlier SAH, and Site (location).
Section 3
Pearls/Pitfalls
Ethanic Variation
The score explicitly accounts for the significantly higher rupture risks seen in Finnish and Japanese populations. This is theorized to be due to genetic factors and differing aneurysm morphology common in these regions. For a patient with identical aneurysm characteristics, a Finnish heritage increases the rupture risk points from 0 to 5, potentially shifting them from conservative to surgical management.
Section 4
Evidence Appraisal
Primary Reference
Development of the PHASES score for prediction of risk of rupture of intracranial aneurysms: a pooled analysis of individual patient data
Greving JP et al. • Lancet Neurol. 2014;13(1):59-66
