Which technology creates a secure, decentralized ledger to store patient data and improve data security, interoperability, and integrity across health systems?

• A. Interoperability
• B. Blockchain
• C. Digital Health Records
• D. Digital Twins

Answer: (B)

Distributed ledger technology, like blockchain, provides a secure, decentralized ledger to store patient data and enhance security, interoperability, and integrity across health systems. Records are grouped into blocks and linked by cryptographic hashes, with a network-wide consensus that validates each addition. This creates immutability—the data cannot be altered without detection—producing a trustworthy audit trail. Access can be tightly controlled through cryptographic keys and smart contracts, enabling authorized providers to share information without exposing everything. In healthcare, this leads to a single, interoperable record across organizations while preserving privacy and patient consent.

Interoperability, while essential, is a goal rather than a technology itself. Digital Health Records are typically centralized systems that can create silos and single points of failure, rather than a decentralized, tamper-evident ledger. Digital Twins are virtual replicas used for simulation and optimization, not primarily for securely storing and sharing real patient data across systems.