2) Manuscript Title: Substituting inpatient with outpatient care after implementing the outpatient mutual-aid insurance program in China: A blessing or a curse?

Background: While the Outpatient Mutual-Aid Insurance Program for Urban Employees (ORIS) has been introduced in many places in China, evidence on its causal impacts on healthcare expenditures remains limited. Methods: This study adopts a quasi-experimental design using a dataset comprising 17,658 inpatients and 4,141 outpatients diagnosed with colorectal cancer from 2018 to 2024 in an eastern city in China. A Difference-in-Differences regression model combined with two-way fixed effects was employed to estimate the effects of ORIS adoption on outpatient expenditures and its spillover effects on inpatient expenditures. Results: Implementing the ORIS was associated with a 168% (P = 0.002) increase in outpatient total expenditures and a 333% (P < 0.001) increase in outpatient out-of-pocket expenditures, while inpatient total and out-of-pocket expenditures decreased by 6% (P = 0.008) and 12% (P = 0.003), respectively. The rise in outpatient total expenditures was primarily driven by a 1,041% (P < 0.001) increase in outpatient drug expenditures, while the decline in inpatient total expenditures was mainly due to a 13% (P = 0.001) decrease in inpatient drug expenditures. Conclusions: This study demonstrated a substitution between inpatient and outpatient care following ORIS adoption. The increase in outpatient total expenditures occurred through two potential mechanisms: 1) shifting care from inpatient to outpatient settings by reducing unnecessary inpatient drug prescriptions, and 2) optimizing the structure of outpatient care by limiting unnecessary diagnostics and examinations. Policymakers are advised to further promote the diffusion of the ORIS, while simultaneously strengthening drug use oversight to curb potential moral hazard. Supplementary Material File (manuscript.docx) - Download - 1.17 MB Information & Authors Information Version history Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 120views 58downloads Citations Download citation Ziyu Xu, Zixuan Peng, Hua Zhang, et al. 2) Manuscript Title: Substituting inpatient with outpatient care after implementing the outpatient mutual-aid insurance program in China: A blessing or a curse?. Authorea. 21 January 2026. DOI: https://doi.org/10.22541/au.176899165.58677399/v1 DOI: https://doi.org/10.22541/au.176899165.58677399/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.