Centralized-Decentralized Health Management System (CDHMS): A Federated Database Architectural Prototype for Healthcare Interoperability

Fragmentation of data is common in the U.S. healthcare system, which leads to substandard patient safety, excess administration waste, and impediments to public health monitoring. This paper proposes a relational database design, the Centralized-Decentralized Health Management System (CDHMS) that achieves a balance between conflicting requirements of local autonomy and federated access to data. The system is based on 15 normalized relations that are organized in 6 functional layers: core clinical infrastructure, Master Patient Index, Interoperability Mapping layer, Audit and Break-Glass logging subsystem, Patient consent and access-control framework, and a Role Based plus Attribute Based Access Control (RBAC+ABAC) model with 6 different user roles. The schema is deployed in MySQL Workbench 8.0 CE, with some sample mock data, and tested using 12 test queries. Results show the architecture enables no duplicate patient identities, reconciliation of incompatible coding vocabularies, granular patient consent management, and a tamper evident audit trail of all patient data access, including emergency overrides.