P1.148. Risk of Institutional Financial Deficit in Esophageal Cancer Surgery: An Analysis Focusing on DPC Margin and Length of Stay

Abstract

Abstract Topic Esophageal Cancer: Other Background Esophagectomy is a highly invasive procedure requiring prolonged general anesthesia, intensive postoperative care, multidisciplinary management, and substantial healthcare resources. Under Japan’s Diagnosis Procedure Combination (DPC) bundled payment system, concerns have been raised regarding institutional financial vulnerability, particularly in cases with postoperative complications. Identifying factors associated with DPC-related financial deficit is essential to ensure both quality of care and institutional sustainability. The aim of this study was to visualize the risk of institutional financial deficit under the DPC system in patients undergoing esophagectomy and to identify its associated determinants. Methods We retrospectively analyzed 113 consecutive patients who underwent thoracoscopic esophagectomy for malignant tumors (procedure code K529-21) between January 2018 and August 2025 at our institution. Clinical data were linked with DPC administrative data. The DPC margin was defined as the difference between the DPC bundled reimbursement and the estimated fee-for-service (FFS) equivalent of actual resource utilization. A negative DPC margin (≤0 JPY) was considered an indicator of institutional financial deficit. Two-dimensional modeling of DPC margin and length of stay (LOS) was performed using spline regression and Gaussian Mixture Model (GMM) clustering to identify deviation patterns. Multivariable analyses were conducted to determine independent factors associated with deviation. Results The cohort comprised 90 men (80%) with a median age of 70 years; 50% had stage III or higher disease. Neoadjuvant chemotherapy and robotic surgery were each performed in 66%. Median postoperative LOS was 22 days. Pulmonary complications occurred in 34%, anastomotic leakage in 8%, recurrent laryngeal nerve palsy in 22%, and cardiovascular complications in 4%. Median DPC reimbursement was 3,634,224 JPY, with a median margin of +256,336 JPY; eight patients (7.1%) had negative margins. Spline regression and GMM clustering identified a standard group (n=101) and a deviation group (n=12) with downward margin deviation. Deviation was significantly associated with older age, pulmonary and cardiovascular complications, and in-hospital reoperation. Multivariable analysis confirmed pulmonary complications, cardiovascular complications, and reoperation as independent determinants. Injection and procedural costs were independently associated with deviation. Conclusion Under the current DPC reimbursement system, the financial safety margin for esophagectomy is limited. Severe postoperative events requiring intensive resource use—particularly cardiovascular complications and in-hospital reoperation—markedly increase the risk of institutional financial deficit. These findings underscore structural vulnerability of bundled payment systems when applied to high-risk surgical procedures.