Channeling Patient Flow in China: An Agent-Based Model of Insurance Reimbursement and Hierarchical Care

In China, the absence of a strict referral system leads to overcrowding in tertiary hospitals and underutilization of primary care, challenging the implementation of a tiered diagnosis and treatment system. This study investigates how differential health insurance reimbursement rates can be leveraged to guide patient flow. We developed an agent-based simulation model, calibrated with real-world data on hypertensive inpatients from Beijing (2015-2017). The model simulated patient healthcare-seeking choices under various reimbursement scenarios for primary, secondary, and tertiary hospitals. Adjusting reimbursement rates significantly redirected patient flow and altered medical insurance fund expenditure. Increasing the reimbursement rate for primary hospitals proved particularly effective in channeling patients toward them. We identified an optimal balance-maximizing the proportion of hypertensive inpatients seeking care at primary hospitals (achieving 36.41%, compared to an observed baseline of 16.39%) while controlling total fund expenditure-when reimbursement rates were set at 95% for primary, 85% for secondary, and 70% for tertiary hospitals. Differential health insurance reimbursement serves as a potent policy lever to steer patient flow within a tiered healthcare system. The agent-based modeling approach provides a valuable tool for policymakers to simulate and identify optimal reimbursement strategies, thereby promoting efficient healthcare delivery and sustainable fund management.