Same loss, different patterns: a diagnostic typology of hospital financial loss based on full-cost accounting

Background Under diagnosis-related group (DRG) payment reform, hospitals require case-level cost information to identify heterogeneous financial risks that department-level accounting may obscure. This study examines these patterns in a single tertiary specialist ophthalmic hospital, focusing on clinical departments with DRG-covered inpatient activity. Methods This study analyzed department-level financial data and patient-level DRG cost data from one tertiary specialist hospital in fiscal year 2024. The descriptive DRG dataset comprised 13,034 cases across 27 DRG groups. After prespecified exclusions, the patient-level analytical dataset comprised 12,579 cases across 15 DRG groups. Analyses included descriptive statistics, group comparisons, multivariable regression with department and DRG fixed effects and heteroskedasticity-robust standard errors, and clustering of 62 department–DRG combinations. Results The overall billed-charge–cost profit (loss) rate for DRG-grouped cases was −26.10%. Medical services accounted for 94.18% of the total loss and had a category-specific profit (loss) rate of −39.13%, compared with +0.07% for materials and −12.17% for drugs. Six DRG groups accounted for 91.49% of the total loss. Profit (loss) rates decreased monotonically with length-of-stay. In the adjusted regression model, each additional inpatient day was associated with a 6.44-percentage-point decrease in the profit (loss) rate. Clustering 62 department–DRG combinations yielded a short-stay, less-severe-loss group ( n = 7), a moderate-stay, moderate-loss group ( n = 50), and a long-stay, severe-loss group ( n = 5). At the aggregate department level, the non-DRG profit (loss) rate (−41.73%) was lower than the DRG rate (−26.10%) while DRG business performed better in 7 out of 11 departments. Conclusion Hospital financial losses were associated with three distinguishable patterns: a concentration of losses in medical services, longer inpatient stays, and differences between DRG and non-DRG business performance. Item- and DRG-level cost accounting can decompose an undifferentiated “loss” into specific, verifiable clues, offering more targeted direction for refined hospital management.