title: The development of differences in hospital costs accross income groups in Finland from 1998 to 2010.
abstract: OBJECTIVE
  To quantify differences in hospital costs between socioeconomic groups and the development over time.
  
  
  METHODS
  Register data on somatic specialised hospital admissions for patients aged between 25 and 84 in Finland in 1998-2010 were used with income data individually linked to them. The cost of an admission was calculated by multiplying the number of a patient's inpatient days by the inpatient day cost of the patient's DRG. We calculated age-standardised admission costs per resident and per user as well as costs per inpatient day and concentration indices separately for men and women.
  
  
  RESULTS
  Hospital admission costs reduced with increasing income. The difference between the extreme income quintiles was more than 50% throughout the study period, and this difference widened. However, the cost per inpatient day was more than 20% higher in the highest income group. The differences between income groups were the most prominent in disease categories involving surgery.
  
  
  CONCLUSIONS
  The growth between socioeconomic groups in hospital costs is presumably mainly due to increasing differences in morbidity. More attention needs to be paid to prevention of health inequalities and access to and content of primary care among low-income groups in order to decrease the need for hospitalisations.
authors.affiliation: Service System Research Unit, National Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland. Electronic address: kristiina.manderbacka@thl.fi.
authors.forename: Kristiina
authors.initials: K
authors.lastname: Manderbacka
authors.affiliation: Centre for Health and Social Economics (CHESS), National Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland. Electronic address: jutta.jarvelin@thl.fi.
authors.forename: Jutta
authors.initials: J
authors.lastname: Järvelin
authors.affiliation: Service System Research Unit, National Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland. Electronic address: martti.arffman@thl.fi.
authors.forename: Martti
authors.initials: M
authors.lastname: Arffman
authors.affiliation: Centre for Health and Social Economics (CHESS), National Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland. Electronic address: unto.hakkinen@thl.fi.
authors.forename: Unto
authors.initials: U
authors.lastname: Häkkinen
authors.affiliation: Service System Department, National Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland; School of Health Sciences, 33014 University of Tampere, Finland. Electronic address: ilmo.keskimaki@thl.fi.
authors.forename: Ilmo
authors.initials: I
authors.lastname: Keskimäki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003953:Diagnosis-Related Groups; D005260:Female; D005387:Finland; D054625:Healthcare Disparities / Q000639:trends*; D017721:Hospital Costs / Q000639:trends*; D006801:Humans; D007182:Income / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data*
keywords: Health services research; Hospital costs; Register-based research; Socioeconomic equity