title: A predictive model of hospitalization cost after cerebral aneurysm clipping.
abstract: BACKGROUND
  Cost containment is the cornerstone of the Affordable Care Act. Although studies have compared the cost of cerebral aneurysm clipping (CAC) and coiling, they have not focused on identification of drivers of cost after CAC, or prediction of its magnitude. The objective of the present study was to develop and validate a predictive model of hospitalization cost after CAC.
  
  
  METHODS
  We performed a retrospective study involving CAC patients who were registered in the Nationwide Inpatient Sample (NIS) database from 2005 to 2010. The two cohorts of ruptured and unruptured aneurysms underwent 1:1 randomization to create derivation and validation subsamples. Regression techniques were used for the creation of a parsimonious predictive model.
  
  
  RESULTS
  Of the 7798 patients undergoing CAC, 4505 (58%) presented with unruptured and 3293 (42%) with ruptured aneurysms. Median hospitalization cost was US$24,398 (IQR $17,079 to $38,249) and $73,694 (IQR $46,270 to $115,128) for the two cohorts, respectively. Common drivers of cost identified in the multivariate analyses included the following: length of stay, number of admission diagnoses and procedures, hospital size and region, and patient income. The models were validated in independent cohorts and demonstrated final R(2) values very similar to the initial models. The predicted and observed values in the validation cohort demonstrated good correlation.
  
  
  CONCLUSIONS
  This national study identified significant drivers of hospitalization cost after CAC. The presented model can be utilized as an adjunct in the cost containment debate and the creation of data driven policies.
authors.affiliation: Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
authors.forename: Kimon
authors.initials: K
authors.lastname: Bekelis
authors.affiliation: Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Symeon
authors.initials: S
authors.lastname: Missios
authors.affiliation: Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA Department of Community and Family Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire, USA.
authors.forename: Todd A
authors.initials: TA
authors.lastname: MacKenzie
authors.affiliation: Section of Vascular Surgery, SUNY Stony Brook, Stony Brook, New York, USA.
authors.forename: Nicos
authors.initials: N
authors.lastname: Labropoulos
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Roberts
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D017721:Hospital Costs; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D002532:Intracranial Aneurysm / Q000191:economics* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D018803:Models, Economic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D013525:Surgical Instruments / Q000191:economics*
keywords: Aneurysm; Economics; Intervention; Subarachnoid