ToolsCalculators
PHASES Score
Estimates 5-year risk of rupture for an unruptured intracranial aneurysm.
PHASES Score
Population
Hypertension
Age >=70 years
Aneurysm size
Earlier SAH from a different, already-treated aneurysm
Aneurysm site
Result0 points
Estimated 5-year absolute risk of aneurysm rupture is about 0.4 %.
- 5-year rupture risk
- 0.4 %
When to use
- Estimating 5-year rupture risk for an unruptured intracranial aneurysm to help weigh observation versus preventive treatment.
Formula
Sum of points for Population, Hypertension, Age >=70, aneurysm Size, Earlier SAH from another aneurysm, and Site, then mapped to a 5-year absolute rupture risk from the derivation cohort's Cox model.
Pearls and pitfalls
- Derived from a pooled analysis of 8382 patients in 6 prospective cohorts.
- Does not capture all rupture risk factors (e.g., aneurysm morphology, smoking, family history) and should complement, not replace, clinical judgement.