Abstract
BACKGROUND: Since the establishment of the National Healthcare Security Administration, China has been actively advancing DRG (Diagnosis-Related Group) reform to address issues related to healthcare fund management and patients’ burden. City C, a major city in southwest China, officially implemented the DRG payment reform in January 2021. The objective of this study is to investigate the changes in hospitalization costs and their structure after the DRG payment reform, providing empirical evidence to optimize health insurance payment policies. METHODS: Using 60,176 valid cases in 62 secondary hospitals and 172,564 valid cases in 52 tertiary hospitals from 2018 to 2021, data were extracted from the local official health insurance platform. An interrupted time series analysis (ITSA) model was employed, with average of hospitalization costs, five cost categories (drug costs, examination costs, etc.), and their respective proportions as the study variables to compare changes before and after the reform. RESULTS: Following the DRG reform, average of hospitalization costs showed an immediate decline of $73.74 in secondary hospitals and $143.59 in tertiary hospitals, with both maintaining downward trends. Cost control was observed in examination costs and material costs in secondary hospitals, and in drug costs and examination costs in tertiary hospitals (P < 0.05). Structurally, there have been few changes in secondary hospitals following DRG reform, but in tertiary hospitals, the proportion of drug costs declined by 2.09% during the 11-month post-reform observation period, while material and treatment costs increased by 1.76% and 2.09% respectively. In addition, heterogeneity tests confirmed that tertiary hospitals achieved greater reductions in drug costs and exhibited more pronounced structural adjustments. CONCLUSIONS: While the hospitalization costs have been significantly controlled following the DRG reform, structural optimization was insufficient and its impact varied by hospital grades. Further deepening of the reform is necessary, with an emphasis on strengthening policy regulation and implementing differentiated strategies to achieve synergistic improvement in cost control and structural optimization. CLINICAL TRAIL NUMBER: Not applicable