title: Evaluating comorbidity scores based on health service expenditures.
abstract: OBJECTIVE
  To describe the performance of Charlson Comorbidity Index (CCI) specifications among Medicare beneficiaries and subgroups.
  
  
  METHODS
  Medicare data for beneficiaries covered by Parts A and B and not Medicare Advantage throughout 2007.
  
  
  METHODS
  We evaluated several CCI specifications, particularly a model using expenditures related to Charlson categories, to predict 1 year mortality.
  
  
  METHODS
  Data were obtained from the Chronic Condition Data Warehouse.
  
  
  RESULTS
  The use of Charlson related expenditures did not result in improved mortality prediction. CCI models perform less well in population subgroups with higher underlying mortality risks based on age and chronic conditions.
  
  
  CONCLUSIONS
  Relatively simple models provide quite adequate discrimination compared to more sophisticated models. Our proposed and more sophisticated model, which added in expenditure information, did not perform as well as much more easily executed methods.
authors.affiliation: UAB-School of Public Health.
authors.forename: Meredith L
authors.initials: ML
authors.lastname: Kilgore
authors.affiliation: UAB-School of Public Health.
authors.forename: Wilson
authors.initials: W
authors.lastname: Smith
authors.affiliation: UAB-School of Medicine.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Curtis
authors.affiliation: UAB-School of Public Health.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Morrisey
authors.affiliation: UAB-School of Public Health.
authors.forename: David J
authors.initials: DJ
authors.lastname: Becker
authors.affiliation: UAB-School of Medicine.
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Saag
authors.affiliation: UAB-School of Public Health.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Delzell
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D006278:Medicare / Q000191:economics / Q000706:statistics & numerical data*; D015233:Models, Statistical; D009026:Mortality; D012737:Sex Factors; D014481:United States / Q000453:epidemiology
keywords: Comorbidity scores; Medicare claims data; risk adjustment