title: What can we learn from international comparisons of costs by DRG?
abstract: OBJECTIVE
  The objective of this study was to compare costs data by diagnosis related group (DRG) between Belgium and Switzerland. Our hypotheses were that differences between countries can probably be explained by methodological differences in cost calculations, by differences in medical practices and by differences in cost structures within the two countries.
  
  
  METHODS
  Classifications of DRG used in the two countries differ (AP-DRGs version 1.7 in Switzerland and APR-DRGs version 15.0 in Belgium). The first step of this study was to transform Belgian summaries into Swiss AP-DRGs. Belgian and Swiss data were calculated with a clinical costing methodology (full costing). Belgian and Swiss costs were converted into US$ PPP (purchasing power parity) in order to neutralize differences in purchasing power between countries.
  
  
  RESULTS
  The results of this study showed higher costs in Switzerland despite standardization of cost data according to PPP. The difference is not explained by the case-mix index because this was similar for inliers between the two countries. The length of stay (LOS) was also quite similar for inliers between the two countries. The case-mix index was, however, higher for high outliers in Belgium, as reflected in a higher LOS for these patients. Higher costs in Switzerland are thus probably explained mainly by the higher number of agency staff by service in this country or because of differences in medical practices.
  
  
  CONCLUSIONS
  It is possible to make international comparisons but only if there is standardization of the case-mix between countries and only if comparable accountancy methodologies are used. Harmonization of DRGs groups, nomenclature and accountancy is thus required.
authors.affiliation: Unité Economie et Gestion des Institutions de Soins, Département d'économie de la santé, Ecole de Santé Publique, Université Libre de Bruxelles, 808, Route de Lennik, CP592, 1070 Bruxelles, Belgium. magali.pirson@ulb.ac.be
authors.forename: M
authors.initials: M
authors.lastname: Pirson
authors.forename: L
authors.initials: L
authors.lastname: Schenker
authors.forename: D
authors.initials: D
authors.lastname: Martins
authors.forename: Duong
authors.initials: D
authors.lastname: Dung
authors.forename: J J
authors.initials: JJ
authors.lastname: Chalé
authors.forename: P
authors.initials: P
authors.lastname: Leclercq
mesh_terms: D001530:Belgium; D019985:Benchmarking; D003365:Costs and Cost Analysis / Q000379:methods; D003953:Diagnosis-Related Groups / Q000191:economics*; D017721:Hospital Costs / Q000145:classification*; D006769:Hospitals, General / Q000191:economics; D038622:Internationality; D013557:Switzerland