title: Homogeneity of the German diagnosis-related groups.
abstract: This study analysed the outstanding homogeneity of the German Diagnosis-Related Groups (G-DRG) using the reduction in variance (R²) of costs. Arbitrary increase in case groups, definition of additional charges and combination of several case groups in one DRG were considered as potential confounders. In 2009, the G-DRG-system offers an outstanding homogeneity with R² of 83.5% in comparison to 2004 with R² of 70.2%. The effect of an arbitrary increase in case groups is negligible. However, a simulation of the other confounders explains three-fourth of the increase in R² between 2004 and 2009. The definition of additional charges attributes in particular to the outstanding homogeneity. The assessment of DRG-systems with R² should be complemented with measures that are independent from a trimming of costs, e.g. relating actual costs with prospective payment. The G-DRGs left medical ground in order to achieve optimal economical homogeneity.
authors.affiliation: Institut für Medizinische Informationsverarbeitung, Biometrie und Epidemiologie (IBE), Ludwig-Maximilians-Universität München, Munich, Germany. juergen.stausberg@ibe.med.uni-muenchen.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Stausberg
authors.forename: Emanuel
authors.initials: E
authors.lastname: Kiefer
mesh_terms: D003365:Costs and Cost Analysis; D003953:Diagnosis-Related Groups / Q000191:economics* / Q000592:standards*; D005858:Germany; D017722:Hospital Charges / Q000145:classification; D015233:Models, Statistical; D009313:National Health Programs / Q000191:economics; D011445:Prospective Payment System / Q000191:economics*; D012051:Reimbursement Mechanisms / Q000458:organization & administration*