Building a new French DRG-classification for non-acute care


Nathalie Raimbaud a, Nicolas Dapzol a, Sophie Baron a, Raphael Schwob a

Introduction
The first classification into medico-economic groups (GME), which was the first step in setting up the activity-based funding for non-acute hospital stays, was implemented in 2013. A new version, using leveraging the same data with another methodology in order to make a synthetic index of the severity of stays, was developed in 2018. Despite convincing results in terms of medico-economic relevance, it was rejected by the providers federation representatives, due to a lack of readability of the casemix. Development resumed in 2019, with the aim of building a classification that is readable for professionals, economically sustainable, while maintaining a reasonable number of groups.

Methods
The work focused on the national databases of non-acute care patient hospitalizations from 2017 to 2018 (2,000,000 stays) and on the corresponding cost database (100.000 stays). The classification is made up of four hierarchical levels addressing different questions. The first hierarchical level, reflecting the medical pathology covered, remains unchanged from the first GME classification. The second level indicates the type of rehabilitation received by the patient: it depends on the age, the quantity of rehabilitation acts carried out during the stay, and whether or not these acts are specialized. The third level translates the level of medico-economic heaviness of the stay, according to the patient's age and dependence, and surgical anteriority. The fourth level, unchanged from the first classification, provides information on the severity of the stay, in connection with other pathologies than the main pathology.

Results
The new classification includes 92 medical groups. Each is divided into rehabilitation groups - pediatric, specialized, quantitatively significant, or other, depending on the type of rehabilitation received. Each rehabilitation group is divided into weight groups, A, B or C, depending on the estimated medico-economic weight. Each weight group is further divided into two severity levels, according to any associated pathologies. The resulting total number of groups is 1144 for full hospitalization and 170 for partial hospitalization. The explanatory power of the model is 19% for the length of stay and 30.3% for costs.

Conclusions
This classification has been in use since March 2022. It has been well received by professionals, due to its good readability: the group codes and labels are understandable and meaningful when reading casemix. Its structure, in four independent hierarchical levels, is adaptable to possible later evolutions of data collection. However, estimating tariffs is harder than before, due to the large number of groups. Prospects for development are identified, with regard to the consideration of rehabilitation in part-time hospitalisation and in pediatrics. In addition, an overhaul of the severity levels is in progress.


a Technical Agency for Information on Hospital Care (ATIH), France

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