A comparative study on the grouping of CHS-DRG 2.0 and 1.1 versions based on empirical analysis

This study aims to compare and evaluate the grouping schemes and performance of China healthcare security diagnosis-related groups (CHS-DRG) versions 2.0 and 1.1, both based on DRG payment systems, in order to provide evidence for optimizing DRG grouping strategies and supporting the further advancement of DRG reform.

A total of 49,117 discharge records from a tertiary hospital in Shanxi Province, collected between January and July 2024, were analyzed. The coefficient of variation (CV) was employed to assess intra-group homogeneity, while the reduction in variation (RIV) was used to evaluate inter-group heterogeneity. Differences in grouping structure and performance between CHS-DRG version 2.0 and version 1.1 were systematically compared.

Following the transition from version 1.1 to version 2.0, the number of DRG groups increased by 7.13%. The proportion of ambiguous cases decreased by 54.86%, and the enrollment rate rose by 1.91%. After trimming, the proportion of groups with CV values below 1 increased by 0.65%. Additionally, the overall CV decreased from 0.37 to 0.36, while the RIV increased from 0.79 to 0.85.

Compared with version 1.1, CHS-DRG version 2.0 demonstrates improved grouping performance. The updated scheme aligns more closely with clinical practice and is supported by more comprehensive policy frameworks. However, further coordination between medical service pricing reforms and DRG implementation remains necessary.