title: Hemodynamic-morphological discriminant models for intracranial aneurysm rupture remain stable with increasing sample size.
abstract: BACKGROUND
  We previously established three logistic regression models for discriminating intracranial aneurysm rupture status based on morphological and hemodynamic analysis of 119 aneurysms. In this study, we tested if these models would remain stable with increasing sample size, and investigated sample sizes required for various confidence levels (CIs).
  
  
  METHODS
  We augmented our previous dataset of 119 aneurysms into a new dataset of 204 samples by collecting an additional 85 consecutive aneurysms, on which we performed flow simulation and calculated morphological and hemodynamic parameters, as done previously. We performed univariate significance tests on these parameters, and multivariate logistic regression on significant parameters. The new regression models were compared against the original models. Receiver operating characteristics analysis was applied to compare the performance of regression models. Furthermore, we performed regression analysis based on bootstrapping resampling statistical simulations to explore how many aneurysm cases were required to generate stable models.
  
  
  RESULTS
  Univariate tests of the 204 aneurysms generated an identical list of significant morphological and hemodynamic parameters as previously (from the analysis of 119 cases). Furthermore, multivariate regression analysis produced three parsimonious predictive models that were almost identical to the previous ones, with model coefficients that had narrower CIs than the original ones. Bootstrapping showed that 10%, 5%, 2%, and 1% convergence levels of CI required 120, 200, 500, and 900 aneurysms, respectively.
  
  
  CONCLUSIONS
  Our original hemodynamic-morphological rupture prediction models are stable and improve with increasing sample size. Results from resampling statistical simulations provide guidance for designing future large multi-population studies.
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Department of Biostatistics, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: Jihnhee
authors.initials: J
authors.lastname: Yu
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: Kenneth V
authors.initials: KV
authors.lastname: Snyder
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: Elad I
authors.initials: EI
authors.lastname: Levy
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: Adnan H
authors.initials: AH
authors.lastname: Siddiqui
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, New York, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Meng
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology* / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D018401:Sample Size
keywords: Aneurysm; Blood Flow; Stroke