Huawei Tan,1 Xueyu Zhang,1 Dandan Guo,1 Shengxian Bi,1 Yingchun Chen,1 Xinyi Peng,1 Hui Yao2 

1School of Medicine and Health Management, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s Republic of China; 2Office of the Medical Community, Huoqiu First People’s Hospital, Lu’an, Anhui, People’s Republic of China

Correspondence: Yingchun Chen, School of Medicine and Health Management, Tongji Medical College, Huazhong University of Science and Technology, 130 hangkong Road, Wuhan, 430030, People’s Republic of China, Email chenyingchunhust@163.com

Purpose: China has developed and widely implemented an innovative case-based payment method for inpatient services under a regional global budget, termed the “Diagnosis-Intervention Packet” (DIP). This study aims to examine cost-shifting behaviour in lung cancer inpatient care under the DIP reform.
Methods: This study examines the impact of the DIP reform in Zunyi, a national pilot city, using double machine learning (DML). Specifically, we analyze the effects on the total health expenditures (THS), individual payments excluding reimbursement (IPER), proportion of IPER, copayments for category-B, proportion of copayments for category-B, copayments for category-C and proportion of copayments for category-C per case for LC inpatients in tertiary hospitals.
Results: The results indicate a significant reduction in THS per case after the DIP reform (β = − 0.0778, p < 0.001). Following the reform, there was a significant increase in IPER (β = 0.0689, p < 0.05), copayments for category-B (β = 0.1682, p < 0.01), and the proportion of copayments for category-B (β = 0.0039, p < 0.05). Conversely, the proportion of copayments for category-C significantly decreased (β = − 0.0108, p < 0.001). Notably, significant heterogeneity in the cost-containment and cost-shifting effects was observed across different hospital categories, teaching types, and insured classifications.
Conclusion: The DIP reform significantly reduced the THS per case for LC inpatients, while shifting in-policy expenditures to IPER. The cost-shifting primarily occurred through the redistribution of copayments from category-C to category-B. It is imperative for policymakers to establish differentiated regulatory policies tailored to various cost categories, hospital types, and insured classifications to optimize the effectiveness of the DIP reform.

Keywords: payment reform, diagnosis-intervention packet, lung cancer, cost containment, cost shifting, China