title: Subarachnoid hemorrhage and the female sex: analysis of risk factors, aneurysm characteristics, and outcomes.
abstract: OBJECTIVE
  The pathophysiology of aneurysmal subarachnoid hemorrhage (aSAH) is unclear. Sex may play a role in the outcome of patients with aSAH.
  
  
  METHODS
  The authors retrospectively identified 617 patients with aSAH (April 2005 to February 2010) and analyzed sex differences in risk factors (age, hypertension, smoking, alcohol consumption, and family history), admission-related factors (World Federation of Neurosurgical Societies grade and admission delay), aneurysm characteristics (site, side, location, and multiplicity), and outcomes (treatment modalities [coiling/clipping/both/conservative], complications [vasospasm and hydrocephalus], length of stay, and modified Rankin Scale score at 3 months).
  
  
  RESULTS
  The female patients with aSAH were older than the male patients (mean age 56.6 vs 51.9 years, respectively, p < 0.001), and more women than men were ≥ 55 years old (56.2% vs 40.4%, respectively, p < 0.001). Women exhibited higher rates of bilateral (6.8% vs 2.6%, respectively, p < 0.05), multiple (11.5% vs 5.2%, respectively, p < 0.05), and internal carotid artery (ICA) (36.9% vs 17.5%, respectively, p < 0.001) aneurysms and a lower rate of anterior cerebral artery aneurysms (26.3% vs 44.8%, respectively, p < 0.001) than the men, but no side differences were noted. There were no sex differences in risk factors, admission-related factors, or outcome measures. For both sexes, outcomes varied according to aneurysm location, with odds ratios for a poor outcome of 1.62 (95% CI 0.91-2.86, p = 0.1) for middle cerebral artery, 2.41 (95% CI 1.29-4.51, p = 0.01) for ICA, and 2.41 (95% CI 1.29-4.51, p = 0.006) for posterior circulation aneurysms compared with those for anterior cerebral artery aneurysms. The odds ratio for poor outcome (modified Rankin Scale score of 4-6) in women compared with men after adjusting for significant prognostic factors was 0.71 (95% CI 0.45-1.11, p > 0.05).
  
  
  CONCLUSIONS
  The overall outcomes after aSAH between women and men are similar.
authors.affiliation: Faculty of Medical Sciences, Newcastle University;
authors.forename: Alhafidz
authors.initials: A
authors.lastname: Hamdan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Barnes
authors.forename: Patrick
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012727:Sex Characteristics; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology*; D020301:Vasospasm, Intracranial / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D055815:Young Adult
keywords: ACA = anterior cerebral artery; ICA = internal carotid artery; MCA = middle cerebral artery; PC = posterior circulation; WFNS = World Federation of Neurosurgical Societies; aSAH = aneurysmal subarachnoid hemorrhage; aneurysm; female; mRS = modified Rankin Scale; outcome; sex; subarachnoid hemorrhage; vascular disorders