Blockchain-Based Data Stores for Healthcare
The healthcare industry provides an excellent opportunity for adopting blockchain technology. Blockchains are designed to maintain the integrity of data. They are immutable—committed data history that cannot be altered or deleted; it can only be updated. For example, using blockchain for patient data would include the following information serving as a digital ledger (building blocks that help make blockchains immutable) that could not be altered:
- Previous & current medications
- Past evaluations
- Past diagnoses
- Previous treatment records
With a blockchain approach, clinicians are empowered to deliver appropriate care based on a trusted and complete history of a patient’s health records while also increasing patients’ engagement with and ownership over their healthcare data.
Dovel has developed a blockchain solution that creates this environment for immutable data while adding a new block of data that holds changes.
Data Integrity
Ledgers have been around for a long time and were typically used to record a history of economic and financial activity between two or more parties. Ledgers found in a blockchain usually consist of the following:
- Current and historical state: A data structure that keeps the current and historical state values, allowing applications to easily access the data without needing to traverse the entire transactional log.
- A journal: A transactional log that keeps a complete record of the entire history of data changes. The transactional log is append-only, meaning that each new record is chained to the previous, allowing you to see the whole lineage of data’s change history. Additionally, with the help of cryptographic hashing, a process that assigns a unique identifier (like a fingerprint) to each record, blocks are chained to one another. This allows ledgers to have a timekeeping property enabling anyone to look back in time and get proof that the data transaction occurred, making auditing simple.
Compare this to relational databases where customers have to engineer an auditing mechanism because the database is not inherently immutable. Such auditing mechanisms built with relational databases can be hard to scale. They put the onus on the application developer to ensure that all the correct data is being recorded.
The auditing mechanism is easier with blockchain since you can easily audit the history of changes to a patient health record, unlike a traditional SQL database, which requires custom coding of some sort to track database changes.
A doctor can easily communicate lab results, visit histories, etc., with a patient, and that patient can easily access those records from a centralized place. Everyone is confident that the records are accurate and haven’t been tampered with or seen by anyone else.
Centralized Ledgers Enable Compliance
Many organizations are interested in blockchain because they need a transparent, immutable, and cryptographically verifiable ledger. Regulatory compliance is a fact of life for healthcare companies. A blockchain approach enables organizations to easily track the controls in place and understand how they have changed over time. In addition, the ledger component of a blockchain solves the problems around data integrity and audit functionality.
*This image contains features of a centralized ledger.
Blockchain-Based Centralized Ledger
At Dovel, we’ve utilized Amazon’s Quantum Ledger Database (QLDB) to build such a solution. Our blockchain-based centralized ledger makes it easy to understand how application data has changed over time, eliminating the need to construct complicated audit functionality within the application. An Amazon QLDB journal is an immutable log where transactions are appended as blocks of data. These blocks are connected with a hash of data (or an immutable cryptographic signature) for verifiability using cryptography. After a transaction gets written as a block into the journal, it cannot be changed or deleted—it becomes a permanent record.
*This image is an example of a QLDB Journal
To ensure that data is well-maintained in the journal, it retains two tables known as the “current state” and “history” tables. The current state table contains the latest state of the data. The history table includes the historical changes made to the data.
In our demo solution, you can see how to enter patient data collected in an exam and see what happens as you continue to update the record, with new blocks of data added. You can check it out for yourself on our Discover platform.