title: Case-mix adjustment and efficiency measurement.
abstract: OBJECTIVE
  The importance of using valid case-mix systems in long-term care is addressed by comparing the predictive power of different case-mix models, and by applying them in the calculation of technical efficiency scores of care units.
  
  
  METHODS
  To construct different case-mix models a statistical clustering technique (Automatic Interaction Detection) was used. Technical efficiency score were calculated using data envelopment analysis (DEA).
  
  
  RESULTS
  The Resource Utilization Groups (RUG-III/22) classification explained 39% of resident specific cost, compared with 16% for a functional dependency scale in the Finnish patient information system HILMO.
  
  
  CONCLUSIONS
  When assessing the economic performance of long-term care units it is important to pay attention to the predictive validity of the case-mix measure to be used. The choice of case-mix measure significantly affected how units were rated in efficiency.
authors.affiliation: Chydenius Institute, Jyväskylä University, Kokkola, Finland. magnus.bjorkgren@chydenius.fi
authors.forename: Magnus A
authors.initials: MA
authors.lastname: Björkgren
authors.forename: Brant E
authors.initials: BE
authors.lastname: Fries
authors.forename: Unto
authors.initials: U
authors.lastname: Häkkinen
authors.forename: Mats
authors.initials: M
authors.lastname: Brommels
mesh_terms: D000203:Activities of Daily Living; D017598:Efficiency, Organizational; D005387:Finland; D006757:Hospital Units / Q000191:economics / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D008134:Long-Term Care / Q000191:economics / Q000592:standards / Q000706:statistics & numerical data*; D015233:Models, Statistical; D009730:Nursing Assessment; D020379:Risk Adjustment