PHASES Score for the Management of Intracranial Aneurysm: A Cross-Sectional Population-Based Retrospective Study

Stroke. 2017 Aug;48(8):2105-2112. doi: 10.1161/STROKEAHA.117.017391. Epub 2017 Jun 30.


Background and purpose: The aim of this study is to assess whether the PHASES score allows to (1) match decisions taken by multidisciplinary team whether to observe or intervene, (2) classify patients being diagnosed with a ruptured versus unruptured intracranial aneurysm (UIA), and (3) discriminate patients at low risk of rupture from the population of patients diagnosed with intracranial aneurysm.

Methods: Population-based prospective and consecutive data were collected between 2006 and 2014. Patients (n=841) were stratified into 4 groups: stable UIA; growing observed UIA; immediately treated UIA; and aneurysmal subarachnoid hemorrhage (aSAH). All patients initially observed were pooled in a follow-up UIA group; patients from growing observed UIA, immediately treated UIA, and aSAH were pooled in a high risk of rupture group. Results are expressed as median [quartile 1, quartile 3].

Results: PHASES scores of immediately treated UIA patients were significantly higher than follow-up UIA group (5 [3, 7] versus 2 [1, 4]). Patients diagnosed with UIA and PHASES score of >3 were more likely to be treated, and the score ≤3 was predictive for observation (areas under these curves=0.74). Odds of being diagnosed with an aSAH were associated with PHASES score of >3 (UIA, 4 [2, 6]; aSAH, 5 [4, 8]; areas under these curves=0.66). Scores of stable UIA patients were significantly lower than high risk of rupture group (2 [1, 4] versus 5 [4, 7]; stable UIA outcome prediction by PHASES score of ≤3: areas under these curves=0.76).

Conclusions: There is a progression of PHASES score between stable UIA, growing observed UIA, immediately treated UIA, and aSAH groups. PHASES score of ≤3 is associated with a low but not negligible likelihood of aneurysm rupture, and specificity of the classifier is low.

Keywords: hypertension; intracranial aneurysm; probability; risk; subarachnoid hemorrhage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cross-Sectional Studies
  • Disease Management*
  • Female
  • Humans
  • Intracranial Aneurysm / diagnosis*
  • Intracranial Aneurysm / epidemiology*
  • Intracranial Aneurysm / therapy
  • Male
  • Middle Aged
  • Population Surveillance* / methods
  • Prospective Studies
  • Retrospective Studies
  • Risk Factors
  • Severity of Illness Index*