On the afternoon of March 22th, 2024, Professor Zhang Chuanchuan, a researcher of the Hundred Talents Program of the School of Economics of Zhejiang University and deputy director of the Institute of Labor Economics of Zhejiang University, was invited to the Yangtze River Forum of Wuhan University to give a special lecture entitled "Medical Insurance DIP Reform and Hospital Response" in the 239 lecture hall of the School of Political Science and Public Administration. The forum was jointly organized by the Institute of Humanities and Social Sciences, the School of Politics and Public Administration, and the Social Security Research Center of Wuhan University, chaired by Associate Professor Zhang Ping of the School of Politics and Public Administration, and attended by more than 50 teachers and students from inside and outside the university.

  Researcher Zhang Chuanchuan uses the policy experiment provided by the reform of medical insurance payment methods to analyze the response of public hospitals and doctors to the policy reform from the perspective of medical supply side. In order to avoid the abuse of medical and health resources and medical insurance funds caused by project-based payment, China has begun to implement the disease score payment (DIP) method based on big data, which combines disease payment and total budget management to achieve cost control. In the context of this policy, researcher Zhang Chuanchuan analyzed the behaviors that hospitals may adopt such as high set of coding, changing the content of medical services, increasing the number of patients admitted, and prevaricating the selection of patients, as well as the impact on patients' health and welfare.

  Based on the practice of DIP system in a provincial capital, researcher Zhang Chuanchuan used the data of the administrative institutions of employee medical insurance and the data of medical insurance hospitalization reimbursement in the region to construct a difference-in-difference (DID) model framework, taking the municipal medical insurance patients who adopted the DIP payment method as the treatment group and the provincial medical insurance patients who did not take DIP as the control group, and estimated the changes in hospital behavior brought about by the DIP payment method reform. The results of benchmark estimation and a series of robustness tests confirm that DIP significantly improves the coding score of inpatients in hospitals. Heterogeneity analysis showed that DIP was more likely to produce high-set coding under disease categories with greater operating space, such as a higher degree of score dispersion. In addition, due to the impact of DIP, hospitals have also undergone certain changes in the content of service provision and the scale of patients admitted, but they have not shown significant prevarication in screening patients. For patients, DIP payments have led to a slight decrease in readmissions in the short term.

  Prof. Chuanchuan Zhang's research is of great value for understanding and explaining the behavioral decision-making of medical service providers under the reform of medical insurance payment methods, and also points out the focus of medical insurance supervision and the possible negative impact of medical insurance reform, which provides an empirical basis for the formulation of medical insurance policies. During the lecture, the teachers and students present actively participated in the interaction, and conducted in-depth exchanges on issues such as high-set code identification, out-of-pocket expenses, policy value weight, and the long-term health impact of the policy on patients, which further broadened the cognitive depth and research horizon of the participating teachers and students.