title: National socioeconomic indicators are associated with outcomes after aneurysmal subarachnoid hemorrhage: a hierarchical mixed-effects analysis.
abstract: OBJECTIVE
  Although heterogeneity exists in patient outcomes following subarachnoid hemorrhage (SAH) across different centers and countries, it is unclear which factors contribute to such disparities. In this study, the authors performed a post hoc analysis of a large international database to evaluate the association between a country's socioeconomic indicators and patient outcome following aneurysmal SAH.
  
  
  METHODS
  An analysis was performed on a database of 3552 patients enrolled in studies of tirilazad mesylate for aneurysmal SAH from 1991 to 1997, which included 162 neurosurgical centers in North and Central America, Australia, Europe, and Africa. Two primary outcomes were assessed at 3 months after SAH: mortality and Glasgow Outcome Scale (GOS) score. The association between these outcomes, nation-level socioeconomic indicators (percapita gross domestic product [GDP], population-to-neurosurgeon ratio, and health care funding model), and patientlevel covariates were assessed using a hierarchical mixed-effects logistic regression analysis.
  
  
  RESULTS
  Multiple previously identified patient-level covariates were significantly associated with increased mortality and worse neurological outcome, including age, intraventricular hemorrhage, and initial neurological grade. Among national-level covariates, higher per-capita GDP (p < 0.05) was associated with both reduced mortality and improved neurological outcome. A higher population-to-neurosurgeon ratio (p < 0.01), as well as fewer neurosurgical centers per population (p < 0.001), was also associated with better neurological outcome (p < 0.01). Health care funding model was not a significant predictor of either primary outcome.
  
  
  CONCLUSIONS
  Higher per-capita gross GDP and population-to-neurosurgeon ratio were associated with improved outcome after aneurysmal SAH. The former result may speak to the availability of resources, while the latter may be a reflection of better outcomes with centralized care. Although patient clinical and radiographic phenotypes remain the primary predictors of outcome, this study shows that national socioeconomic disparities also explain heterogeneity in outcomes following SAH.
authors.affiliation: Division of Neurosurgery, St. Michael's Hospital; Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital; Department of Surgery, University of Toronto, Ontario, Canada; and.
authors.forename: Daipayan
authors.initials: D
authors.lastname: Guha
authors.forename: George M
authors.initials: GM
authors.lastname: Ibrahim
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Kertzer
authors.forename: R Loch
authors.initials: RL
authors.lastname: Macdonald
mesh_terms: D000465:Algorithms; D017542:Aneurysm, Ruptured / Q000628:therapy; D003627:Data Interpretation, Statistical; D005260:Female; D023261:Glasgow Outcome Scale; D059066:Gross Domestic Product; D006801:Humans; D008297:Male; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000627:therapeutic use; D009493:Neurosurgery / Q000706:statistics & numerical data; D011281:Pregnatrienes / Q000627:therapeutic use; D012959:Socioeconomic Factors; D013345:Subarachnoid Hemorrhage / Q000191:economics / Q000453:epidemiology* / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D018696:Neuroprotective Agents; D011281:Pregnatrienes; C053355:tirilazad
keywords: CI = confidence interval; GDP = gross domestic product; GOS = Glasgow Outcome Scale; HHH = hypertension, hypervolemia, and hemodilution; ICC = intraclass correlation coefficient; ICH = intracerebral hemorrhage; IVH = intraventricular hemorrhage; OR = odds ratio; SAH = subarachnoid hemorrhage; WFNS = World Federation of Neurological Societies; random effects analysis; socioeconomic indicators; subarachnoid hemorrhage; tirilazad; vascular disorders