Introduction
Disease control and prevention efforts undertaken by public health organizations focus on the detection of emerging threats to the health of the population. Currently healthcare providers report cases to the state health departments via paper based reports or completing online forms8. The State Departments then alert the Centers for Disease Control (CDC) making the process often not fast enough for identifying the onset of epidemics.
An epidemic refers to an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area7. Analyzing the reported cases and declaring an epidemic in real time is the need of the hour. Only when an outbreak is declared publicly, can preventive measures be undertaken by healthcare providers (and or government agencies) to save lives.
The Centers for Disease Control does share information about infectious diseases with local as well as state health departments. However, sharing the critical information in an efficient and timely manner has been difficult2. Privacy of patient data poses its own constraints as it should be accessible only by medical professionals with proper credentials. Currently certain processes are carried out manually to make sure these privacy standards are met. Data from different sources has to be funneled, cleaned, validated and analyzed, all of which causes delays which is not ideal for disaster response3. Managing the data as it is shared by the CDC, local and state health departments, as well as medical providers is very complicated currently5.
Today, technological advances have enabled progress and efficiency in all walks of life. We propose a blockchain solution that would make the process of collection and analysis of reported cases as well as declaration of an epidemic far more efficient.
Blockchain is a peer to peer distributed ledger technology that establishes transparency and trust. It consists of a distributed network, shared ledger and digital transactions.
Each network member has an identical copy of the blockchain and is part of the collective process of validation and certification of transactions for the network. The transactions are recorded on a shared ledger. New transactions are added after a majority of members verify the transaction’s validity by running algorithms to evaluate it. Once a transaction is added to the shared ledger, it cannot be changed or removed.
The digital transactions can contain any type of information or digital asset, defined by the network implementing the blockchain. Transactions are structured into linear block ordered chronologically, with each block containing a hash to the prior block in the blockchain.
Why Blockchain
Being a distributed ledger technology that uses public-key cryptography, a blockchain system offers a high level of security. Smart contracts can be pre-programmed to analyze incoming data and issue an alert based on any of a list of triggers. This can take out the time lag that exists in the system today.
Blockchain technology has the following advantages over current solutions10, 11:
1. Fast transaction: Blockchain-based transactions are processed 24/7 all year round. Unlike manual data processing, there is no time lag as data addition, updates and transactions happen in real time.
2. The key information related to diagnosis is available to all
3. Security: Private information is encrypted and available only to those with the key. The risk of fraud and tampering are lowered due to the distributed network.
4. Decentralization: There is no central system, the networks distributed and the blockchain is resilient, without the need of one single database, and the important actionable information is published.
5. Transparency and immutability: Blockchain is open source technology so making alterations to the logged data in the blockchain is not possible without everyone seeing the change.
6. Process integrity: All transactions are executed exactly as the protocol specifies.
Proposal
Patient and associated medical diagnosis and treatment data can be collected from healthcare providers via APIs to existing EHR systems or by simple daily data exchange in industry standard formats. The patient centric data would be stored in a highly secure data tier (i.e. data lake) while the diagnosis centric data is stored in the public blockchain . All stored information would be encrypted and signed digitally to ensure privacy and authenticity. This distributed hash table with open participation of all the players (the CDC, local and state health departments, as well as medical providers) and custom access control mechanisms allows for a system that takes in to account patient privacy6.
Health data being dynamic and expansive, it would not be replicated to every member of the network, instead the blockchain would store a complete indexed history of all the health data in hashed format and additionally the diagnosis centric data in open raw un-hashed format. Each block would contain a unique key (link to the health record), time stamp and meta data about the medical data4.
Each time a medical record is added, its authenticity is verified by a digital signature. The health data is then encrypted and stored in the data tier. A unique pointer to this data along with the diagnosis data (non personal information) is registered in the blockchain along with the user’s unique identifier. Each time a medical record is added, a smart monitoring application would check if any infectious disease occurrence thresholds are crossed. If the occurrence thresholds are crossed then CDC and healthcare industry would be immediately alerted.
Implementation
Our custom application would process data exported daily from existing Electronic Health Record (EHR) systems at healthcare providers (hospitals, outpatient clinics, imaging centers etc.) and:
1. post the diagnosis and non-personal information to an Ethereum Smart Contract on a blockchain ledger
2. and post the patient data along with doctor reports and images to a data lake.
The application can support business rules, data-mapping and batch job and would allow the user to click a button to push data from various healthcare providers on to the block chain. We will have a set of GUI screens and scheduler jobs, to initiate the data sync. The application will use authentication and authorization modules for secure and authentic data exchange between the healthcare provider EHR systems and the block chain.
Why Ethereum?
Ethereum has a really matured ecosystem that allows any centralized application to be decentralized, with zero downtime, while keeping the data immutable, corruption and tamper-proof as well as secure9. It allows for Smart Contracts and decentralized applications where one can decide on ownership rules, as well as formats and functions of transactions12. Its open source platform, flexibility and transparency have made it the ideal platform for Smart Contracts and distributed applications for mass consumption.
Medical data format
Our solution will allow for patient data to be uploaded in a few different formats, including FHIR7.
Conclusion
Our solution will allow for real time access, analysis and monitoring of critical illness information. This in turn will allow for faster response from the CDC to prevent the spread of infectious diseases. Patient data privacy concerns are taken care of by handling only meta data at the blockchain level, and the remaining data being encrypted and stored in the secure data tier. Patient data access controls will be held by the patient who would be able to give access to others.
References
1. Blockchain For Health Data and Its Potential Use in Health IT and Health Care Related Research, Laura Linn, Martha B. Koo https://www.healthit.gov/sites/default/files/11-74-ablockchainforhealthcare.pdf
2. https://futurism.com/the-cdc-wants-to-use-blockchain-as-a-weapon-against-deadly-epidemics/
3. https://www.coindesk.com/us-centers-disease-control-launch-first-blockchain-test-disaster-relief/
4. https://www.healthit.gov/sites/default/files/11-74-ablockchainforhealthcare.pdf
5. https://www.technologyreview.com/s/608959/why-the-cdc-wants-in-on-blockchain/
6. A Blockchain-Based Approach to Health Information Exchange Networks; Kevin Peterson, Rammohan Deeduvanu, Pradip Kanjamala, and Kelly Boles, Mayo Clinic
7. https://www.cdc.gov/ophss/csels/dsepd/ss1978/lesson1/section11.html
8. http://journals.sagepub.com/doi/full/10.1177/0033354916670871
9. https://blockgeeks.com/guides/ethereum/
10. https://blockchaintechnologycom.wordpress.com/2016/11/21/advantages-disadvantages/
11. https://www.fool.com/investing/2017/12/11/5-big-advantages-of-blockchain-and-1-reason-to-be.aspx
12. http://radiostud.io/eight-blockchain-platforms-comparison/