Table 2. PHASES score to estimate the 5-year aneurysm rupture rate [8].

PHASES: population, hypertension, age, size, earlier subarachnoid hemorrhage, and site, ICA: internal carotid artery, MCA: middle cerebral artery, PCoA: posterior communicating artery, SAH: subarachnoid hemorrhage, ACA: anterior cerebral arteries.

PHASES Aneurysm Risk Score
Criteria	Points
Population
North American, European (other than Finnish)	0
Japanese	3
Finnish	5
Hypertension
No	0
Yes	1
Age
<70 years	0
≥70 years	1
Size of aneurysm
<7.0 mm	0
7.0-9.9 mm	3
10.0-19.9 mm	6
≥20.0 mm	10
Earlier SAH from another aneurysm
No	0
Yes	1
Site of aneurysm
ICA	0
MCA	2
ACA/PcoA/posterior circulation	4