To evaluate the impact of diagnosis-related group(DRG) payment reform on medical resource utilization and healthcare quality among hospitalized lung cancer patients, so as to provide critical insights into China's healthcare payment reform and enhance medical efficiency and quality.

A retrospective analysis was conducted using medical records from a tertiary oncology hospital in Shandong province, with a focus on patients diagnosed with malignant lung tumors between January 28, 2021 and April 16, 2024. A self-paired design was implemented, with October 26, 2021 serving as the intervention point. Data from the same patients were collected for two periods: pre-DRG payment (January 28, 2021-October 25, 2021) and post-DRG payment (October 26, 2021-April 16, 2024). An interrupted time series(ITS) regression model was employed to compare the changes in medical resource utilization indicators (e.g., length of stay, total hospital expenses, reimbursement expenses, out-of-pocket expenses, number of chemotherapy/radiotherapy sessions, number of targeted/immunotherapy sessions, and number of nursing examinations) and healthcare quality indicators, including the incidence of major complications or comorbidities (MCC), complications or comorbidities (CC), and 30-day readmission rates.

A total of 944 patients were included in the analysis, with 49.4% male and 50.6% female; 67.1% were under 65 years of age, while 32.9% were 65 years or older. After the DRG payment, there was a significant reduction in length of stay (β₂=-3.235, P < 0.001), total hospital expenses (β₂=-5155.900, P < 0.001), reimbursement expenses (β₂=-2120.350, P=0.020), and out-of-pocket expenses (β₂=-3035.555, P < 0.001). However, the number of chemotherapy/radiotherapy sessions, targeted/immunotherapy sessions, and nursing examinations did not exhibit significant changes. The incidence of MCC/CC significantly increased (β₂=3.011, P < 0.001), whereas the 30-day readmission rate remained unchanged.

The DRG payment reform effectively reduces medical costs and shortens hospitalization duration, thereby enhancing hospital management efficiency. However, it may also lead to an increased incidence of complications, which could potentially affect healthcare quality. Therefore, the possible implications of DRG reform on healthcare quality should be carefully monitored and addressed.