Analysis and Optimization of Inpatient Cost Structure for Fracture Patients Under the Implementation of the DRG Policy

Changgeng Su¹Jiuhui Su²Xin Li²Xinyan Jin³Zhiyue Wang¹Jiwei Liu¹Hongjuan Wen^1*

• ¹Changchun University of Chinese Medicine, Changchun, China
• ²Haicheng Orthopedic Hospital, Haicheng, China
• ³Monitoring and Statistical Research Center of the National Administration of Traditional Chinese Medicine, BeiIJing, China

Background: Fractures are among the most common traumatic injuries in China, with rising incidence due to aging, traffic accidents, and sports injuries, imposing a heavy economic burden. To enhance cost efficiency, China launched a nationwide Diagnosis-Related Groups (DRG) payment reform in 2019. While DRG effectively controls costs in chronic diseases, its impact on trauma such as fractures remains unclear due to complex and variable treatments. Most prior studies focus on epidemiology, lacking economic evaluation under DRG. This study assesses how DRG reform affects inpatient cost structures of fracture patients and differences across comorbidities and fracture types.Methods: Data from 12,101 fracture inpatients (ICD-10 S22–S92) at a tertiary hospital in Liaoning (2018–2024) were analyzed. Structural change analysis evaluated shifts in cost composition before and after DRG reform. Interrupted time series (ITS) modeling estimated immediate and trend effects of the policy introduced on July 1, 2019. Grey relational analysis quantified the contribution of each cost category to total expenses.Results: After DRG implementation, median drug cost fell by 18.1% (3,416.06→2,796.74 CNY), while consumables slightly increased (7,358.12→7,465.64 CNY; p<0.05). Therapeutic and surgical costs rose moderately, indicating a shift toward technical services. Rehabilitation costs decreased for some fractures (S72) but increased for others (S82), reflecting heterogeneity. Structural variation was highest in consumables for spinal fractures (S32, DsV=2170.42%) and drug costs for femoral fractures declined (S72, DsV=-39.78%). Patients with comorbidities showed greater cost adjustments (15.3% higher DsV; p<0.01). ITS showed significant post-policy changes (p<0.05): S32 total costs reversed from rising (β₁=1247.93) to falling (β₃=-2467.0). Diagnostic costs rose for most fractures but fell in S32 (β₃=-227.16); S72 increased (β₃=52.86). Medication and treatment costs declined overall, most strongly in S32 (β₃=-355.1). Consumables rose in S42 (β₃=1578.62), and rehabilitation decreased across all types, most in S32 (β₃=-483.58). Grey relational analysis showed fracture-specific structural shifts: diagnostic and drug costs became more concentrated in S22 and S42, while S52 and S62 declined across categories.Conclusion: DRG reform reduced drug expenses but increased diagnostic and consumables costs, indicating structural shifts and fracture-type heterogeneity. These results highlight the need for refined, type-specific management strategies and provide evidence for optimizing DRG payment standards in China.