The Italian research project for the prospective payment of hospital rehabilitation care notes on a work in progress

Prospective payment of inpatient rehabilitation services has been suggested or implemented in several countries. The current Italian system classifies patients into 5 broad groups based on MDCs. MDCs are the parent partition of the DRG classification and are meaningless in the rehabilitation setting, a specific classification of inpatient rehabilitation care is thus obviously needed. The fundamental goal of an isoresource classification is building clinically homogeneous discharge groups with the smallest possible within-the-group resource consumption variability. Existing models of patient assessment and classification are presented and their strengths and shortcomings are discussed. The basic characteristics of a satisfactory model are defined and methods of model building are briefly described. No assessment tool looks completely satisfactory, but to accept a limited set of information means accepting the variable selection and the association methods of existing classifications. The selection of variables and the attribution of variable weights in the classification system must be a verifiable end point and not the starting point of analysis. A relationship between explanatory variables and outcome must be sought, not only as a tool to organize and group the costs of the observed events, like CART, but also as an instrument to foresee the reasonable costs of the events to come. Several grouping methods must then be tested and compared against CART (Correlation And Regression Trees), like Search Partition Analysis (SPAN), main components analysis, cluster analysis, multivariate analysis. The objectives of our research are a manageable assessment tool where only positively tested information will be retained and a classification system which could be considered an intelligible and equitable "iso-resource" classification system.