DRG Payment Reduces Hospitalization Costs and Length of Stay Without Compromising Quality in COPD Patients: An Interrupted Time Series Study

Background Globally adopted as a value-based reimbursement reform, the Diagnosis-Related Groups (DRG) framework demonstrates tripartite healthcare governance effects: curbing excessive medical expenditures, rationalizing bed-day allocation, and optimizing clinical service delivery. This study conducts empirical analysis of DRG implementation's multidimensional impacts (2016-2023) on COPD inpatients' hospitalization economics (cost structure), care efficiency (bed-day utilization), and outcome quality (30-day readmission rates) at a regional medical center, establishing evidence-based insights for healthcare payment system modernization. Methods Using an interrupted time series design (2016-2023), this study analyzed DRG reform's impacts on hospitalization costs, bed-days, and care quality in COPD patients at at the People's Hospital of Ningxia Hui Autonomous Region. Results This study analyzed 14,998 COPD hospitalizations (mean age: 73.67±1.13 years; 55.32% male). The analysis demonstrated distinct expenditure patterns across payment phases. During the DRG/DIP reform period, diagnosis costs showed increases of 641.10 CNY (95% CI 330.74-951.45) with parallel rises in treatment expenses (180.77 CNY; 95% CI 94.84-266.70), accompanied by a 0.68% reduction in length of stay (95% CI -1.29% to -0.08%). Following full DRG implementation, significant financial shifts emerged: total hospitalization costs decreased by 1071.31 CNY (95% CI -2038.25 to -104.36) despite concurrent increases in diagnostic charges (917.96 CNY; 95% CI 631.34-1204.58), therapeutic costs (271.62 CNY; 95% CI 202.10-341.14), and pharmaceutical expenditures (760.09 CNY; 95% CI 451.47-1068.70), while material costs demonstrated a 217.06 CNY reduction (95% CI -352.23 to -81.86). Remained statistically unchanged were medical service fees, hospitalization duration, mortality rates, and 31-day readmission metrics. Conclusions This study found payment reforms had varying effects: Pre-DRG and DIP phases increased diagnostic/therapeutic spending but shortened hospital stays, while DRG implementation curbed total costs (especially materials) yet increased service and drug fees, without compromising care quality or safety.