Evaluation of cost homogeneity among pediatric inpatients under DRG system: a study of inpatient encounters in Chengdu and Hangzhou, China

The hospitalization costs of treating patients in the same DRG group should be homogeneous, and in different DRG groups should be heterogeneous. However, the current payment standard for the same DRG group is uniformly across hospitals of different tiers, with no consideration for the variations in treatment costs incurred by hospitals at different levels. Moreover, the existing DRG grouping for pediatric cases needs to fully consider the unique characteristics of pediatric diseases, rather than merely rely on a unified framework shared with adult patients. A retrospective analysis was performed on pediatrics inpatient encounters enrolled in the DRG payment system from January to June 2025, with the data sourced from the National Healthcare Security Administration. A total of 289,026 pediatric inpatient encounters were included in the present study. We evaluated the disparities in medical costs between pediatric patient encounters with common diseases and those with idiopathic diseases. Three ADRG groups, namely ES3, DT1 and EX2, exhibited a consistent trend: the higher the hospital level, the higher the average hospitalization expenses for each subgroup. The average hospitalization costs for Kawasaki disease and Anorectal malformation complicated with rectal malformation were significantly higher than those of their respective ADRG groups, with the differences being statistically significant. The implementation of DRG payment should take pediatric clinical characteristics into account. Refined grouping adjustments shall be performed for disease groups with high cost heterogeneity to improve the adaptability of the DRG system to pediatric cases.