Difference between revisions of "The Blockchain in Healthcare"

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A '''personal health record (PHR)''' is an [[Web based EMR|internet-based]] [[EMR|electronic medical record]] that allows patients to electronically manage and organize their personal health information. It permits the patients to take ownership over their own healthcare information, including the ability to maintain a lifelong patient history, and to retain control over the content and access of the PHR. PHR is a separate system from the electronic or paper medical-record system maintained by healthcare providers. <ref name="markle phwg 2003">The Personal Health Working Group Final Report. July 1, 2003. Markle Foundation. http://www.connectingforhealth.org/resources/final_phwg_report1.pdf</ref>
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The blockchain is an idea centered around the concept of a secure, digital ledger system that provides a system for efficient, auditable transactions of almost any type between entities <ref>Tapscott D, Tapscott A. Blockchain Revolution: How the Technology Behind Bitcoin Is Changing Money, Business, and the World. United States: Portfolio; 2016. 1-368 p.</ref>. All information related to blockchain transactions is at once both independently verifiable by all (even outside) parties as correct and also inscrutable to entities without explicit permission. The first and probably most well-known implementation of blockchain technology is [https://bitcoin.org Bitcoin] <ref name="BTC">Nakamoto S. Bitcoin: A Peer-to-Peer Electronic Cash System. WwwBitcoinOrg [Internet]. 2008;9. Available from: https://bitcoin.org/bitcoin.pdf</ref>, but there has been a massive expansion of blockchain use-cases since Bitcoin's initial introduction.
  
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== What is a PHR? ==
 
  
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The National Committee on Vital and Health Statistics (NCVHS) determined that there is no uniform definition of a PHR in industry or government. This lack of consensus makes collaboration, coordination, and policy making difficult. <ref name="Clarke 2006">Janice L. Clarke, Deborah C. Meiris. Electronic Personal Health Records Come of Age. American Journal of Medical Quality May/June 2006 vol. 21 no. 3 suppl 5S-15S. http://ajm.sagepub.com/content/21/3_suppl/5S.extract</ref>
 
  
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However, some common themes arise.
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== What is the Blockchain? ==
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* Markle Foundation: An electronic application through which individuals can access, manage and share their health information, and that of others for whom they are authorized, in a private, secure, and confidential environment". <ref name="markle phwg 2003"></ref>
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* American Health Information Management Association (AHIMA): "an electronic, universally available, lifelong resource of health information needed by individuals to make health decisions. Individuals own and manage the information in the PHR that is collected from healthcare providers or entered by the individual. The PHR is maintained in a secure and private environment with the individual determining rights of access, it is separate from and does not replace the legal record of any provider" <ref name="tang 2005">Tang PC, Ash JS, Bates DW, Overhage JM, Sands DZ. Personal health records: definitions, benefits, and strategies for overcoming barriers to adoption. J Am Med Inform Assoc. 2006 Mar-Apr;13(2):121-6. Epub 2005 Dec 15. http://www.ncbi.nlm.nih.gov/pubmed/16357345</ref>
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* a PHR is the patient's interface to a healthcare provider's electronic health record
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* a consumer or patient-managed health record.
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PHRs offer an integrated and comprehensive view of health information, including information people generate themselves" and "The PHR is a single, person-centered system designed to track and support health activities across one’s entire life experience; it is not limited to a single organization or a single health care provider” [2]. This definition further identifies a platform for PHR operation and incorporates the lifelong span of individual’s information collection and management. Beside owners’ ability to view their own healthcare information created by them, it provides the ability to view clinical data and information entered and or generated by their providers and medical care institutes. Furthermore, it introduces three key aspects of the PHR, comprehensive, integrated with other systems and applications, and accessible from anywhere via internet.
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First, it should be clear that there is no one blockchain to rule them all.  "The Blockchain," as it is often referred, really is a concept of a series (chain) of interrelated sets (blocks) of encrypted information. Hence a chain of blocks, or blockchain. There are many such blockchains in existence, and one could choose to do transactions on any one of them or create a new blockchain.
  
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== Functionality ==
 
  
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The PHR is a portable electronic record keeping tool that provides functions easy to use and understand, customizable to fit personal need in information retrieval, display and access, and helps individual to organize personal health information. Furthermore, helps individuals with general health education, and educates them about their personal health information. Another PHR functional attribute is that, its flexibility to expand to support evolving health needs of individual and family. <ref name="ahima phr contents">What Should Your PHR Contain?. October 2003. The American Health Information Management Association (AHIMA). http://www.myphr.com/your_record/record_contents.asp</ref>
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An important aspect of most blockchains is that they are designed to be maintained on a distributed network of multiple nodes. Each node holds a complete copy of the blockchain and adds each sequential new block as it is created. This system allows every transaction on the blockchain to be verified by any or all of the nodes in the network, and also makes it very difficult for the information held in the blockchain to become lost or unavailable if any one or even most of the nodes go offline.
  
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PHR Attributes defined by The Personal Health Working Group – Markle Foundation <ref name="markle phwg 2003"></ref>
 
  
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# Each person control his or her own PHR, Individuals decide which parts of their PHR can be accessed, by whom and for how long.
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Transactions that are set to be added to the blockchain are added to the newest block as soon as it is created. This makes the continued existence of the blockchain dependent on the creation of new blocks. There are several main methods for the creation of new blocks on the network, and the choice of method depends somewhat on the purpose of the blockchain in question. Bitcoin, the first cryptocurrency, uses a method called [https://en.wikipedia.org/wiki/Proof-of-work_system Proof of Work System (Wikipedia)]:
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# PHRs contain information from one’s entire lifetime.
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* In the traditional Proof of Work System, each block validator, or "miner," competes to validate the block by processing a task. The winner is the first person to complete this task. The chance of completion of the task is random based on a hash function, but increases with the more "work" a person puts into the task. The system can automatically vary the difficulty of the task to limit the speed of block generation. The winner is credited for his/her work by a small amount of currency.  
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# PHRs contain information from healthcare providers.
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# PHRs are accessible from any place at any time
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# PHRs are private and secure
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# PHRs are “transparent.” Individuals can see who entered each piece of data, where it was transferred from and who has viewed it.
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# PHRs permit each exchange of information with other health information systems and health professionals.
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Results from Harris Interactive survey in April 2002 about Patient-Physician online communication - asked; “If you could do so, which of the following would you like to be able to do online with your doctor or doctors?” - shows (77%) want to ask questions without a visit to the doctor office, (71%) want to make an appointment, (71%) want to request prescriptions refills for medications, (70%) wants to receive the results of medical tests, (6%) none of these, and (4%) don’t know [4]. This survey shows that two thirds of the people surveyed are interested in four defined key PHR functions that are not limited to these four functions. As PHR provides easy access to all of the individual health related information to view and share with the healthcare provider for care planning treatment and preventive care management, the process where PHR provides dynamic and comprehensive information set and presents it at the time of care, itself is core functionality [5].
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The blockchain has moved beyond simply processing transactions of cryptocurrency such as Bitcoin.  Any data that can be encoded into a cryptographic [https://en.wikipedia.org/wiki/Hash_function hash] can be added to a blockchain. Various different ideas have been proposed, and I will not attempt to list them here, but they are wide ranging. Melanie Swan predicts three phases of blockchain adoption: Blockchain 1.0, 2.0, and 3.0<ref>Swan, M. (2015). Blockchain: Blueprint for a new economy: " O'Reilly Media, Inc."</ref>. Blockchain 1.0 manifested as online currency. Blockchain 2.0 is the near future, where blockchain is used to keep track of contracts, financial records, public records, and ownership of property. Blockchain 3.0 will be applied into science, medicine and education.
  
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The Markle Foundation Connecting for Health Initiative Group defines the internet based PHR by its functions as introducing internet based transaction and services. One function is the ability of the healthcare provider to access the PHR, not only, to view but also update information and communicate it to patient. <ref name="markle phwg 2003"></ref>
 
  
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Another function is the integration to the Electronic Health Record (EHR) of the healthcare setting if applicable. To use the PHR to provide certain services, the information entities in the PHR require management and maintenance beside the initial entry, a PHR function included by the Connecting for Health Initiative Group 2004 report is the management of the following type of information: identification and demographic, personal contact, medical insurance, pharmacy insurance, and medical care provider contact. Services the PHR can provide also include drug interaction checking, online prescription request and refills, and preventive service and appointments reminder. Anther set of functions that can help in documentation and data organizing is a health data tracking utility to create charts and graphs, and patient diaries to document information about pain, symptoms, and possible drugs side effects. An important function of the internet based PHR described in the report is the ability to schedule appointment on line with a health care provider. One function PHR can also provide that can store and update medical data and patient information for frequent access, is the summarization into standardized specialist visits forms or questionnaires and patient specific instructions for frequent hospital visits. Other relevant functions that can be integrated and utilized easily in the internet based PHR - defined as optional  - are links to knowledge bases, and links to patient education, self-care content and consensus guidelines. Two PHR functions - viewed as benefits - that might not be often used, or even rarely, are the inclusion of Advance Directive Form and Continuity of Care Record [6-7].
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=== Blockchain Development Groups ===
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Certainly a non-exhaustive list . . .
  
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=== Privacy Access and Control ===
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* [https://bitcoin.org/en/ Bitcoin]
  
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Most privacy policies of PHR systems do not provide an in-depth description of the security measures that they use. Moreover, compliance with standards and regulations in PHR systems is still low. While PHR must be private and secure; [[Giving Patients Control of Their EHR Data | control]] is by the owner who assumes responsibility for the information in it. PHR should be accessible any place any time by the individual and provide means to emergency access to provider when needed.
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* [https://hyperledger.org The Hyperledger Project]
  
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Some of the unanswered questions about privacy in PHR include-
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* [https://ethereum.org The Ethereum Project]
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* Who manages the data in the PHR?
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* What data are managed?
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* What is the source of information used?
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* Who manages the access control to the data in the PHR?
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* What types of permission exist?
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* Who can receive access permission?
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* Is an audit of access to data in the PHR performed? Who can see this audit?
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=== Maintenance and Security ===
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* [https://r3cev.com/blog/2016/4/4/introducing-r3-corda-a-distributed-ledger-designed-for-financial-services The CORDA Platform]
  
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An audit trail is required as part of the PHR, and to maintain data integrity, data can be changed or deleted only by the original source under the given authority of the owner, and the owner decides what is incorporated into the record.
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* [http://www.muskokagroup.org/ The Muskoka Group]
  
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[[PHRs and HIPAA]]
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* [https://oncprojectracking.healthit.gov/wiki/display/TechLabI/Blockchain+Challenge+on+ONC+Tech+Lab The ONC Tech Lab]
  
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=== Interoperability ===
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== Blockchain Use Cases ==
  
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The PHR should be a standard driven tool, exchanging and communicating easily, consistent and accurately with systems. The PHR has a structured data collection and storage, and the ability to link to knowledge, educational, and other databases.
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=== Cryptocurrency ===
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Bitcoin (BTC) was the first cryptocurrency based on the blockchain and was developed by someone calling himself (or herself) Satoshi Nakamoto. The protocol was introduced in 2008 after the publication of a white paper<ref name="BTC" /> describing the algorithm and the mechanisms for generation and distribution of BTC. At this point there are hundreds of cryptocurrencies in circulation according to [http://wikipedia.org Wikipedia], many of which are based on the Bitcoin blockchain, but only a few have gone into widespread use<ref>https://en.wikipedia.org/wiki/List_of_cryptocurrencies</ref>.
  
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The Markle Foundation Connecting for Health Initiative Group is the first to produce a definitive set of characterizations of the PHR, list (3) contains seven attributes categories to the PHR as defined by the group. <ref name="markle phwg 2003"></ref> Although the context of these attributes categories explained by the attributes and functions published by (e-HIM) group, the Markle Foundation report classified them into what is available today and which ones are not easy to achieve. With many attributes can be available today to implement in PHR, the attributes that are difficult to achieve include the entire lifelong health information records and the acquiring of the provider's legal or electronic records.  Interoperability classified as an attribute available today, but only for a small number of patients, and mainly for data associated with single a source [6].
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=== Smart Contracts ===
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One of the major potential functions of blockchain technology is through the creation of smart contracts.  Various components of contracts, including proof of the involved parties, requirements for completion, and actions upon completion of the contract can be encoded in blocks. These can then be added to a blockchain and become available for independent verification, which can even lead to automatic processing of contracts when their requirements have been fulfilled.
  
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==== Standards ====
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Smart contracts are scripts which have various rules and logic that automatically execute when those rules are met. Smart contracts allow heavily automated workflows between transacting parties in the network while maintaining anonymity. Once the contract has been executed, one can take custody over assets or pre-defined payments can be issued. <ref>Christidis, K & Devetsikiotis, M. (2016, May 10). Blockchains and Smart Contracts for the Internet of Things. IEEE Access, 4, 2292-2303. doi: 10.1109/ACCESS.2016.2566339</ref> They are importantly different in the sense that they are stored on a distributed network and they can be verified as true without knowledge of the contract specifications <ref>https://bitsonblocks.net/2016/02/01/a-gentle-introduction-to-smart-contracts/</ref>.
  
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#[[HL7 CDA]]
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[https://ethereum.org The Ethereum Project] was one of the first to introduce the concept of smart contracts using their alternative blockchain and currency token, [https://www.ethereum.org/ether ether].
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#[[openEHR]]
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#[[ASTM CCR]] <ref name="astm standards withdrawn">Standard Specification for Relationship Between a Person (Consumer) and a Supplier of an Electronic Personal (Consumer) Health Record (Withdrawn 2014) http://www.astm.org/Standards/E2211.htm</ref>
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#[[DICOM]]
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==Integration of EMRs and PHRs==
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=== Securities Exchanges and Finance ===
  
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A patient can edit their PHR via a [[patient portal]].
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One of the hottest arenas for blockchain development currently is in the financial markets, an extension of the original cryptocurrency use cases for the blockchain. Multiple stock markets and other financial firms have initiated investigations and pilot projects into the feasibility and utility of the blockchain for contracts and tracking of financial instruments.  NASDAQ has been one of the first major markets to put blockchain technology into use, and has released some information on its implementation, called Linq <ref>http://ir.nasdaq.com/releasedetail.cfm?releaseid=948326</ref><ref>http://www.coindesk.com/hands-on-with-linq-nasdaqs-private-markets-blockchain-project/</ref>. The cryptocurrency website [http://www.coindesk.com Coindesk] has also produced a list of 10 exchanges using or investigating blockchain technologies<ref>http://www.coindesk.com/10-stock-exchanges-blockchain/</ref>.
  
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A personal health record "is an Internet-based set of tools that allows people to access and coordinate their lifelong health information and make appropriate parts of it available to those who need it." It includes "information from their pharmacies and insurance companies" and providers. While "the PHR is separate from and does not replace the legal record of any provider" by one definition, integration of the electronic medical record by presenting provider-entered data in the context of a web-based PHR, provides added benefits to the consumer. Securing this personal health information promotes adoption of PHRs by the consumer. <ref name="phr ahima">The Role of the Personal Health Record in the EHR October 2003. The American Health Information Management Association (AHIMA). http://library.ahima.org/xpedio/groups/public/documents/ahima/bok1_027539.hcsp</ref>
 
  
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Inclusion of secure messaging with one's provider in combination with viewing one's own clinical data allows for an interactive only relationship with the provider over a common set of health data.
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Additionally, financial firms such as Visa have been experimenting with the blockchain for keeping track of transactions as well as with proof of concept applications such as remittance<ref>http://www.coindesk.com/hands-on-with-visa-europes-bitcoin-remittance-app/</ref>.
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The technology available to present this data is primarily through creating secure data views of EMR data repositories. A security system requiring multifactor authentication and encrypted pages (SSL) is essential.
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Consumer surveys indicate an interest in this functionality and additional features, such as, aggregating information from all providers, a task for regional health information organizations (RHIOs). <ref name="phr ahima"></ref>
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== Advantages and Disadvantages of Blockchain ==
  
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===Patient entered data===
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Blockchain is a novel concept and is being explored in various sectors. While there may be several applications and limitations of this technology in future, some of them are highlighted below<ref>Fauvel, W. (2017, August 11). Blockchain Advantage and Disadvantages. Medium. Retrieved from: https://medium.com/nudjed/blockchain-advantage-and-disadvantages-e76dfde3bbc0</ref>:
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=== Pros: ===
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# Distributed: There is no single owner of the database. As anyone can contribute and be a part of the network, the risks of data tampering and fraud are minimal. As Nakamoto <ref name="BTC" /> mentioned, as long as the majority of nodes are honest, a random attacker would not be able to alter the history.
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# Trustless: As every node in the network will have a copy of the blockchain and they verify the transactions independently. Hence, this system allows transaction even if the parties don't trust each other.
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# Immutable: Once the transaction is verified and embedded in the blockchain, it is almost impossible to undo it, and the complexity increases with time as more blocks are added downstream. This allows keeping a track of accurate events that occurred through the history.
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# Decentralized: There is no middleman like banks or data owners. This helps avoid manipulation of the market by the owners.
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=== Cons: ===
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# Waste of resources: As several nodes are running and utilizing a huge amount of computing power and electricity to verify and maintain the blockchain, there is more than required redundancy.
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# Higher cost for less value: With time, the use of network increases and the complexity of the hashing algorithm also increases. Hence, more resources are required for the same amount of work. This increases the cost of work and transactions gets slower, as miners prioritize the transactions with higher incentives causing a backlog the transactions with smaller values.
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# Difficulty to keep up with the size of the block: As the size continues to grow along with the complexity to solve the calculation, new nodes with smaller computing power will have difficulty joining the network and likewise, the older and slower nodes will gradually fade with decreasing incentive for the work. Hence, like Darwin’s theory of the "survival of the fittest", a few larger nodes will dominate the network creating more and more centralization of the system.
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# Speculative market: Due to the lack of proper regulation of this system, the market is subject to a great volatility and thus making it risky for investors.
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# Immutable smart contracts: As there are clear advantages of having permanent and immutable records, at the same time, there is a bitter flipside to this. For example, if there is a flaw with code that can compromise the system, it is also irreparable and creates the opportunity for the attackers to exploit the same flaw repetitively in future. As time progresses, the capability of repairing the error will be even more complex.
  
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[[Patient entered data]]
 
  
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===Benefits of Tethered PHR===
 
  
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[[Tethered PHR]]
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=== Possible Solutions: ===
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* The issues with resource wastefulness and diminishing return of investment are mainly an issue with Proof-of-Work Systems, and can be improved with new blockchain innovations such as [https://en.bitcoin.it/wiki/Proof_of_Stake Proof of Stake (Bitcoin Wiki)] or blockchain scaling<ref>Croman, Kyle, et al. "On scaling decentralized blockchains." International Conference on Financial Cryptography and Data Security. Springer, Berlin, Heidelberg, 2016.</ref>
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** There are some issues with the original Proof of Work that Satoshi created: 1) it was very resource intensive and 2) as the bitcoin reward becomes harder to obtain as the blockchain grows, there is less incentive to mine. With fewer miners come fewer validators of the block which could allow malicious actors to introduce fake block into the chain. An alternative to Proof of Work is Proof of Stake<ref>Siim, Janno. "Proof-of-Stake."</ref>. In Proof of Stake, the amount of work a user can do depends on their "wealth," or the amount of currency they own (if they own 1% of the currency, they can mine 1% of the block). In order for someone to manipulate the block, they have to own more than a majority of the currency (51% or more), making successful attacks on the blockchain very expensive. Furthermore, the attack would devalue the currency, resulting in a big hit to the attacker.
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** Currently, all computers that participate in mining a blockchain process every transaction. This is very slow and resource wasteful. A solution to this is to calculate how many computers will be needed to validate a new block, and give the task of verifying a transaction to those computers. This will allow parallel processing (scaling) of "blocks" and speed up transactions. At this point, the details behind how to manage this division of tasks without compromising security still being worked out.
  
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===PHR 2.0===
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== Potential Use Cases in Healthcare ==
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Though there has yet to be a breakthrough report or use-case for blockchain technology in healthcare, there are many potential ways that the blockchain could be implemented within the current healthcare structure.  Any list will likely be incomplete, but these examples represent some of the published and available literature on blockchain implementations in health.
  
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Personal Health Records are private, however, society’s willingness to share information can lead to patient empowerment and knowledge. Personal Health Record 2.0, as postulated by Gunther Eysenbach [http://gunther-eysenbach.blogspot.com]
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=== Health Information Exchange (HIE) ===
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, is grounded in the belief that users freely share pertinent data with other users. Certain sections are available for a controlled set of users or the public as a whole to see. That data can then be combined and shared with a tethered EHR. There is an enhanced ability to learn and thus be empowered.  Eysenbach feels this is a disruptive concept and is not without a large measure of risk [http://gunther-eysenbach.blogspot.com/2008/06/from-patient-needs-to-personal-health.html].
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One major area that blockchains may be able to facilitate is the secure access to and communication of patient health records between individuals and institutions. There have been multiple white papers published on the topic, including groups from the Mayo Clinic <ref>Peterson K, Deeduvanu R, Kanjamala P, Boles K. A Blockchain-Based Approach to Health Information Exchange Networks. (1):1–10.</ref> and MIT <ref>Ekblaw A, Azaria A, Halamka JD, Lippman A, Original I, Vieira T. A Case Study for Blockchain in Healthcare: “ MedRec ” prototype for electronic health records and medical research data MedRec: Using Blockchain for Medical Data Access and Permission Management [Internet]. 2016. Available from: https://www.healthit.gov/sites/default/files/5-56-onc_blockchainchallenge_mitwhitepaper.pdf</ref> who described a system for patient information exchange based on blockchain technology that would allow patient-controlled access to records across institutions using HL7 Fast Healthcare Interoperability Resources ([[FHIR]]), [http://json.org JSON], or other encoding system. In these models the actual health care data are not encoded in the blockchain, but are merely references pointing to where the data reside, such as at institutions or in a "data lake" <ref>Linn LA, Koo MB. Blockchain For Health Data and Its Potential Use in Health IT and Health Care Related Research. 2014;1–10.</ref>. Similarly, a group out of China described an app called Healthcare Data Gateway (HGD) that allows patients to view and directly control rule-based access to their health records with a smart phone interface and authentication provided by a blockchain network <ref>Yue X, Wang H, Jin D, Li M, Jiang W. Healthcare Data Gateways: Found Healthcare Intelligence on Blockchain with Novel Privacy Risk Control. J Med Syst [Internet]. 2016 Oct;40(10):218. Available from: http://dx.doi.org/10.1007/s10916-016-0574-6</ref>. These ideas support the concept of patient-owned medical data, and would have the effect of decentralization of medical records in ways that are as yet undetermined.
  
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An example of the PHR 2.0 concept is PatientsLikeMe.com [http://www.patientslikeme.com/] and onpatient.com [http://www.onpatient.com/]. PatientsLikeMe was created as an attempt to find a cure for amyotrophic lateral sclerosis and was based on the idea that if patients are allowed to share their data with each other, better approaches to treatment could be achieved. PatientsLikeMe is the largest database of ALS patients to date, and has partnered with a company called 23andMe, Inc. to create a "genetics search engine" for the ALS community. This allows patients with ALS to share genetic information. A data intensive social network such as this can be incorporated into Eysenbach’s concept of the PHR 2.0.
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=== Health Research Integrity ===
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Academic research is a major driver of advances in health care, but in the setting of limited funding and publication pressures on researchers significant concerns have been raised regarding research integrity<ref>Titus SL, Wells J a, Rhoades LJ. Repairing research integrity. Nature [Internet]. 2008 Jun 19;453(7198):980–2. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18563131</ref>. Organizations such as [http://clinicaltrials.gov ClinicalTrials.gov] and others have been developed to help drive researchers to define endpoints and analysis prior to conducting clinical trials and other studies. As it represents an immutable, verifiable record of events and transactions, the blockchain has been proposed as a potential decentralized resources for helping to ensure biomedical research integrity. Benjamin Carlisle<ref>Carlisle BG. Proof of prespecified endpoints in medical research with the bitcoin blockchain [Internet]. 2014. Available from: http://www.bgcarlisle.com/blog/2014/08/25/proof-of-prespecified-endpoints-in-medical-research-with-the-bitcoin-blockchain/</ref>, followed by several researchers from the UK<ref>Irving G, Holden J. How blockchain-timestamped protocols could improve the trustworthiness of medical science. F1000Research [Internet]. 2016;5:222. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866630/</ref>, proposed in 2014 that researchers could use the blockchain to record pre-specified aspects of their projects, including the study design, analysis plan, and data structure, among others, which could later be verified by consumers of the literature to decrease bias that may be introduced in post-hoc analysis<ref>Slade E, Drysdale H, Goldacre B, COMPare Team. Discrepancies Between Prespecified and Reported Outcomes. Ann Intern Med [Internet]. 2016 Mar 1;164(5):374. Available from: http://www.ncbi.nlm.nih.gov/pubmed/26720309</ref>. The blockchain also offers the potential ability to verify the integrity of actual research data and analysis by outside observers, even if the data themselves are not made publicly available. These types of implementations may lead to improvements in both the integrity of biomedical research as well as bolster public trust in medical research.
  
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onpatient was created as a moblie PHR that was a replacement for Google Health.
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=== Personal Health Records ===
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This concept dovetails with the idea of HIE using the blockchain, but focuses more on the secure maintenance of a personal health record (PHR) by patients. No production PHR has been released based on this technology, but concepts such as MedVault <ref>Baxendale G. Can Blockchain Revolutionise EPRs? [Internet]. Vol. 58, ITNOW. 2016. p. 38–9. Available from: http://itnow.oxfordjournals.org/lookup/doi/10.1093/itnow/bww017</ref> use alternative blockchains such as [http://www.Colu.com Colu] to store patient data directly on the blockchain. Others such as [https://devpost.com/software/ehealthwallet eHealthWallet] have also developed prototype PHRs based on the blockchain. Patients could then share or authorize doctors and other health entities to access and modify their data.
  
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===PHR Challenges===
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The majority of the proposals leverage blockchain’s ability to maintain an immutable record to place control of patient’s health record into their hand by allowing them to grant and revoke access to their medical records according to their preference<ref>Gordon, W. J., & Catalini, C. (2018). Blockchain Technology for Healthcare: Facilitating the Transition to Patient-Driven Interoperability. Comput Struct Biotechnol J, 16, 224-230</ref><ref>Yue, X., Wang, H., Jin, D., Li, M., & Jiang, W. (2016). Healthcare Data Gateways: Found Healthcare Intelligence on Blockchain with Novel Privacy Risk Control. J Med Syst, 40(10), 218. doi:10.1007/s10916-016-0574-6</ref>.
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* In a traditional system, patient’s health record is kept and maintained by a health care organization (e.g. hospital, clinic, etc.). Information can be freely shared between the organization and a Regional Health Information Organization (RHIO) or another organization that has a business agreement with the originating institution. If there is no business agreement between the institutions, one-off requests can be made, but this will take time and delay care.
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[[PHR Challenges]]
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* As Meaningful Use Stage 3 is being implemented at health care organizations, there has been a push to create patient-facing application programming interfaces (APIs) that allow patient to directly retrieve their record from the institution and share it with the provider as needed.
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* A blockchain-enabled smart contracts controlled by the patient can be used to authorize direct sharing of medical record between institutions. Patient can specify the subset of the record to be shared or set an expiration date on the authorization.
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==Types of Information in Personal Health Record==
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The information in PHR in its electronic version can be entered in many format and from many different sources, personally entered by the owner of the PHR, and professionally by the health care provider, manually or automatically when integrating with other professional healthcare systems and applications. The PHR serves as a core repository for personal health information that identifies the patient clinical data - similar to information in the provider version of electronic medical record - utilized by the individual or health care provider to perform actions and/or help in the joint decision making process. The key feature of this accumulation of multi source information is that its all kept and presented in one entity. List (1) contains a summary of most common information types in the PHR defined by AHIMA. For more of detailed information types and as a start point to establishing a Personal Health Record, AHIMA recommends a set (List 2) of information collected by PHR owner from the various patient medical records sources [3]. <ref name="phr ahima"></ref>
+
−
 
+
−
=== Minimum Common Data Elements in PHR===
+
−
 
+
−
* Personal Demographic Information
+
−
* General medical information
+
−
* Allergies and drug sensitivities
+
−
* Conditions
+
−
* Hospitalizations
+
−
* Surgeries
+
−
* Medications
+
−
* Immunizations
+
−
* Clinical tests
+
−
* Pregnancy History
+
−
 
+
−
 
+
−
=== Information collected by PHR owner from the various patient medical records sources===
+
−
 
+
−
* People to contact in case of emergency
+
−
* Names, addresses, and phone numbers of physician, dentist, and other specialists
+
−
* Health insurance information
+
−
* Living wills and advance directives
+
−
* Organ donor authorization
+
−
* A list and dates of significant illnesses and surgeries
+
−
* Current medications and dosages
+
−
* Immunizations and their dates
+
−
* Allergies
+
−
* Important events, dates, and hereditary conditions in family history
+
−
* A recent physical examination
+
−
* Opinions of specialists
+
−
* Important tests results
+
−
* Eye and dental records
+
−
* Correspondence between provider(s)  
+
−
* Permission forms for release of information, operations, and other medical procedures
+
−
* Any information wish to include about one's health, such as exercise regimen, any herbal medications and any counseling may received.
+
−
 
+
−
==Attributes of Personal Health Record==
+
−
 
+
−
PHR attributes can crossover some of the functions defined for a PHR and can deduce its benefits or advantages. The (e-HIM) Work Group - was formed as an initiative by AHIMA that focuses on PHR to formulate its guidelines - organized six attributes categories for PHR. <ref name="ahima phr">The Role of the Personal Health Record in the EHR Appendix A: Attributes of the PHR. October 2003. The American Health Information Management Association (AHIMA). http://library.ahima.org/xpedio/groups/public/documents/ahima/bok1_027455.hcsp</ref>
+
−
+
−
# Ownership: Defines the owner of the PHR, as the person who controls and owns information, and decides which parts of their PHR accessible, by whom and for how long.  
+
 
   
 
   
 +
Gordon et al. suggested five features of block chain that allow for successful patient-driven interoperability<ref>Gordon, W. J., & Catalini, C. (2018). Blockchain Technology for Healthcare: Facilitating the Transition to Patient-Driven Interoperability. Comput Struct Biotechnol J, 16, 224-230</ref>:
 +
* Digital access rules: The blockchain-enabled digital access rule is centralized, which makes it accessible by multiple institutions, while facilitating editing of the rules by the patient at any moment via a smart phone-based or web-based application
 +
* Data aggregation: Patient could also aggregate their data (or metadata) across institutions to a blockchain or another secured location using the digital access rule, thus creating a complete record of their health
 +
* Data liquidity: Because the change in digital access rules will take effect as soon as the patient (or legal representative) approves it, data can be share rapidly to the requesting institution, allowing access to time-sensitive information such as allergies, “code status,” etc.
 +
* Patient identity: Even though there is no national patient identifier, institutions can use the blockchain-assigned individual’s public key and match it with their local identifier to start sharing data across systems
 +
* Data immutability: Since all changes made to the blockchain is recorded and immutable, the risk of loss is minimized, and the record can be audited at any time.
  
−
The PHR model that provides individuals with online access to their secured data professionally, as described by Markle Foundation, consist of two functional models [6].
+
There are several limitations of the current state of technologies for blockchain-based personal health records:
 +
* The first concern with block chain is its inability to handle the transaction volume of clinical data. Blockchain is great at keeping a record of changes to a small amount of data (such as account balance, owner’s identity, etc.). However, it is not economically practical to store a large amount of data on the blockchain due to cost associated with creating a very large ledger to store this information and to perform proof-of-work on this ledger. Proposed solutions include:
 +
** Validate data using a different approach to consensus such as proof-of-stake.
 +
** Store a summary of, instead of a complete clinical report.
 +
** Patient’s data can be stored on a permissioned (private) regional blockchains that are built to handle large transaction volumes without time-intensive validation.
  
−
=== Institutional gateway model ===
+
* A second limitation of blockchain is the lack of privacy and security. Even though the identifier on the blockchain is the cryptographically generated public key, this is only pseudonymous, as patient can still be identified by matching for other basic demographic information, and once the public key has been linked to the patient, their activity on the blockchain can be tracked. A few solutions to this problem has been proposed:
 +
** Use permissioned (member-only) blockchain to avoid public exposure.
 +
** Basic demographic information stored on a block chain can also be encrypted to prevent access.
 +
** Store sensitive data off-chain, with on-chain data focusing on granting permission to access requested data using pointers and metadata. This would also allow patients to assign different access rule for different users of their data
  
−
The institutional gateway model connects the PHR to a single institution and it is the main source of data. These gateways collect information from secured multiple services within the institution, or from secured single service
+
* Since the focus of many blockchain-based projects is on patient-controlled health care data, it necessitates more patient participation than the traditional, institution-based paradigm. They must be able to assign certain permissions for different institutions that request access.
 +
** Having a patient-friendly “app” to manage public keys and permissions will become very important to get more buy-in from patients.
 +
** Patient will also need to keep track of their password to gain access to their private key in order to make changes to the block chain. There will need to be a mechanism for recovering lost password when this occurs.
  
−
architecture models: Third-Party Repository where a third party database stores centrally data from both the PHR and provider systems with the patient consent.
+
* The largest barrier to widespread adoption of blockchain in healthcare deals with the issue of incentives. Meaningful Use stage 3 requires implementation of patient-facing API, but this does not entail handling access control of healthcare record to patient. Institution has little incentive to pay for the cost of setting up a blockchain just to give patient more control even though this will improve interoperability. To overcome this, a few proposals have been made:
 +
** Expand federal incentives to patient-controlled medical record.
 +
** Researchers can be incentivized to pay for the setup of these blockchains by gaining access to patient anonymized data for research purposes.
  
−
=== Aggregator model ===
+
=== Storage of Health Care Data ===
 +
Most of the previous examples use the blockchain not as a direct data storage medium, but instead as a secure reference point for identities, access, and data locations.  At least one group from a company called Tierion, which partners with the [http://www.2.forms.healthcare.philips.com/blockchainlabs Philips Blockchain Lab ], has produced a concept called Chainpoint<ref>Vaughan AW, Bukowski J, Wilkinson S, Sporny CM, Shea R, Allen C, et al. Chainpoint: A scalable protocol for anchoring data in the blockchain and generating blockchain receipts [Internet]. 2016. Available from: https://tierion.com/chainpoint</ref>, which proposes to use a [https://proofofexistence.com/about Proof of Existence] concept and Merkle Roots<ref>Merkle RC. PROTOCOLS FOR PUBUC KEY CRYPTOSYSTEMS. In: IEEE Symposium on Security and Privacy [Internet]. 1980. p. 122–34. Available from: http://www.merkle.com/papers/Protocols.pdf</ref> to efficiently store actual patient records on the blockchain without imposing excessive transaction demands on the system.
  
−
The aggregator model, as an application that gathers information form the patient and from multiple professional sources with a multiple or single service, or pull data from multiple institutions across multiple types of services.  
+
=== Billing and Claims Adjudication ===
 +
Blockchain system can help reduce administrative costs and time while automating claims adjudication and payment processing using smart contracts. For example - a smart contract is set up between payer or insurance company, provider, and patient such that when the patient sees a provider, or if a procedure is done, an entry is recorded in the blockchain. Based on the criteria set, the contract can automatically issue reimbursement from the payer as well as co-pay from the patient without having to wait for the insurance approval.<ref>Srinivasan, P. (2017, November 9). Healthcare Blockchain: How Smart Contracts Could Revolutionize Care Delivery. Prolifics. Retrieved from: https://www.prolifics.com/blog/healthcare-blockchain-how-smart-contracts-could-revolutionize-care-delivery</ref>
  
−
architecture models: Record locator service, where a third party has a repository of identifying information about an individual – the only thing held centrally- then authorizes and securely queries and request data for a particular patient from all the participating professional health data sources as data not held centrally, but generated on demand.
+
=== Drug Supply Chain and Prescription Management ===
 +
Counterfeit drugs are a major problem especially in the developing country where it is estimated that about 1 in 10 medical products are counterfeit <ref>WHO. (2017, November 28). 1 in 10 medical products in developing countries is substandard or falsified. Retrieved from: http://www.who.int/en/news-room/detail/28-11-2017-1-in-10-medical-products-in-developing-countries-is-substandard-or-falsified</ref>. Ensuring the integrity of the drug and maintaining a robust audit trail is a must to ensure patient safety. Similarly, this platform can be used in prescription drug management and track history and authenticate prescriptions using smart-contracts.  
  
−
Patient health records, traditionally, have been owned and accessed by health care providers.  The IOM report ''Crossing the Quality Chasm'' recommended the "patients should have unfettered access to their own medical information." HIPAA regulations mandate that patients be allowed access to their records.  Patients will want access to their records online, as electronic records become more prevalent. Advantages to patient access of their records include giving patients a more powerful role in their own care, allowing them to correct inaccuracies, encouraging them to have a better understanding of their health issues, and promoting trust and communication.  On the other hand, providers express concern that they will need to abridge or omit parts of the record that are sensitive and that patients could become unnecessarily concerned about things they do not understand.
+
=== Few Examples of Current Use Cases and Future Development ===
  
−
Drs Halamka, Mandl, and Tang describe 7 challenges in Early Experiences with Personal Health Records:
+
* MedRec- it is based on Ethereum platform and focuses on medical data management using smart contracts like managing permissions and authentication processes, data sharing in an interoperable environment between healthcare systems and maintaining an audit log. <ref>Azaria, A., Ekblaw, A., Vieira, T., & Lippman, A. (2016, August 22-24). MedRec: Using Blockchain for Medical Data Access and Permission Management. 2016 2nd International Conference on Open and Big Data (OBD). doi:10.1109/obd.2016.11</ref>
  
−
* Should the entire problem list be shared?
+
* Guardtime- also focuses on medical data management and has partnered with e-Health authority of Estonia to secure the country's database of health records <ref>Ruubel M. (2016, February 12). Estonian eHealth Authority Partners with Guardtime to Accelerate Transparency and Auditability in Health Care. Retrieved from: https://guardtime.com/blog/estonian-ehealth-partners-guardtime-blockchain-based-transparency</ref>. Also, recently, MyPCR smartphone platform from Guardtime has partnered with Instant Access Medical and Healthcare Gateway in the UK for patient health data management and verification of medication adherence. <ref>Ruubel M. (2018, June 20). World’s first blockchain-supported Personal Care Record Platform launched by Guardtime and partners to up to 30 million NHS patients in the UK. Retrieved from: https://guardtime.com/blog/world-s-first-blockchain-supported-personal-care-record-platform-launched-by-guardtime-and-partners</ref> 
−
* Should the entire medication list and allergy list be shared?
+
−
* Should all Laboratory and diagnostic test results be shared with the patient?
+
−
* Should clinical notes be shared with the patient?
+
−
* How should patients be authenticated to access the PHR?
+
−
* Should minors be able to have their own private PHR?
+
−
* Should the PHR include secure clinician/patient messaging?
+
  
−
The first 4 sharing issues were resolved over three different systems in similar ways.
+
* Blockchain Health- created for healthcare research data management where users can individually authorize the release of their health information to researchers as well as track the use of their data. <ref>BlockchainHealth. (2016). Blockchain for health research. Retrieved from: https://blockchainhealth.co/</ref>
  
−
* Problem lists were shared.
+
* BlockMedx- it is a startup company which intends to use the blockchain platform to transmit DEA controlled drug prescriptions from physicians to pharmacies and then to patients securely. <ref>BlockMedx. (2018). Retrieved from: https://blockmedx.com/en/</ref>
−
* Medication, and allergy lists were shared.
+
−
* Results were shared in this fashion ==1) at one system, normal results were released to patients within one day and abnormal results within 3 days so that
+
−
* all results were communicated without fail,  but clinicians had a chance to communicate the results first, 2) at the second, all results were released to patients immediately except for HIV results due to state laws, and pathology and MRI/CT cancer staging results held for 1 week to allow personal clinician/patient communication, and 3) all results were shared.
+
−
* Full text clinical notes were not shared in any of the three systems.
+
−
* User authentication, critical to PHR privacy and data integrity, was by user name and password, granted by face to face identification or by written signature verification.
+
−
* In two systems, patients under 18 were not able to have their own personal PHR. In the third, a children’s hospital, the challenge was handled this way == children less than 12 had limited or no access to their record but their guardians had full access, patients 12-18 and their guardians has access to the record but specific parts could be restricted by either, and patients 18 and over had complete access and control of their records.
+
−
* All three systems used secure messaging as part of the PHR. Providers were not flooded with messages; rather electronic messages replaced a similar number of phone calls.  But legal liability concerns and the fact that online medical advice is not often reimbursed were issues.
+
  
 +
* MediLedger- another pharmaceutical supply chain management startup company who has partnered with several drug manufacturers and aims to provide an open, secure and interoperable network. <ref>MediLedger. (2018). The MediLedger Project. Retrieved from: https://mediledger.com/</ref>
  
−
==Potential==
+
* Drug and Pharmacy Verification - [https://devpost.com/software/veripharm VeriPharm] has developed a proof of concept that would help track and verify pharmaceuticals from the raw materials to the final product administered to patients.
  
−
Personal Health Records (PHR) – Today and Future Potential
+
* Appointment Scheduling on the Blockchain - [https://devpost.com/software/dhva-appointment-blocks dhva-apointment-blocks]
  
−
Health care is migrating to care centered on the individual, thus allowing the individual more interaction and participation in his or her health care. This opens new doors for individuals, permitting them to take a more active role in their health care. It allows individuals access to their health record, permits certain health information to be self-entered; requests prescription refills; retrieves copies of their health records; and tracks vital signs including blood sugars and pressures, weight and heart rate. Additionally, the PHR will provide access to health resources. New doors are also being opened for the health care provider, especially if the PHR is integrated with the electronic health record (EHR), enabling the provider to realize benefits in patient care. It will enable the provider to make better medical decisions in the treatment of the individual.
+
* Care Coordination - Projects such as [https://devpost.com/software/simplyvitahlth simplyvitahlth] are geared toward coordinating care between multiple providers and at different institutions to ensure that complex care pathways are being followed appropriately.
  
−
Today, online PHR services are being offered by many health care organizations and vendors. PHR systems range in complexity from stand-alone to full seamless integration with EHR systems. Each system has advantages and disadvantages. The stand-alone application allows for greater security but the information is not shared and it is doubtful whether individuals will be resolute in maintaining its currency. The preferred system is the integrated PHR. 
 
−
 
−
A longitudinal (lifetime) health care record, containing relevant subjective and objective data from various sources including the individual and health care providers, should be established, thus providing a rich resource of useful data for the individual’s health care. While there are no standards for what data the PHR should contain, it is recommended that the data source be identified. Some suggested data types include: problem list; allergy; immunizations; medications; diagnostic test results; personal tracking of vital signs including blood sugars and pressures, weight and heart rate; and others. In a 2011 study by [[Designing a patient-centered personal health record to promote preventive care| Krist et al]], the authors developed a patient centered interactive preventive health record (IPHR) designed to deeply engage patients in preventive care and health promotion. The IPHR provided recommendations for preventive care based on practices recommended by the U.S. Preventive Services Task Force (USPSTF) and other organizations as well as the individual patient history. IPHR was intended to function as a longitudinal record and reminder system for patients and clinicians.
 
−
 
−
For the most part, there has been some reluctance in the adoption of the PHR. One impediment for this lack of acceptance may be attributed to the costs of such systems. Deciding who should pay, the providers, individuals, or perhaps the health care payers appears unresolved. Other obstacles may include technical issues (such as interoperability - without it data cannot be shared), legal issues (including privacy and negligence), and the level of an individual’s desire to use, maintain, and authorize sharing of their PHR. Although as a concept the PHR has great potential in improving the management of health care, there remain many impediments to overcome before it is successful.
 
−
 
−
 
−
In 2001, the Institute of Medicine published Crossing the Quality Chasm. They suggested that health care should be patient centered. At the same time. electronic health records were being developed and improved.  However, compatibility from system to system has remained a large problem despite attempts at standardization such as HL7.  So the electronic health record has been helpful to physicians within their own groups while unavailable to other providers.  Possibly of greatest concern has been how to obtain data in an emergency.
 
−
 
−
In 2010, meaningful use standards were developed in order for physicians to obtain incentive ARRA money. One of the requirements appears to be the patient being provided access to their medical record electronically. In a study in the AMIA Annual Symposium Proceeding in 2006, a study was performed to evaluate the use of PHR's in the elderly. They described multiple barriers to their use including:
 
−
#access to PHR systems
 
−
#access to computers or devices
 
−
#cognitive disabilities
 
−
#physical disabilities
 
−
low computer or reading literacy
 
−
They were able to use a PHR but the great majority required supervised help.
 
−
 
−
One suggestion for increasing the availability of information when it is needed is the Portable Personal Electronic Health Record (PPEHR).
 
−
This can consist of a flash drive with a USB port or a credit card sized card with either a USB connection or possibly a magnetic strip or chip.
 
−
This has been sold commercially and has been offered at very limited cost to patients who belong to certain medical practices such as Kaiser Permanente in California or Connecticut Multispecialty Group in Connecticut.
 
−
 
−
As an example, Kaiser is able to put the following information on it's drive:
 
−
#Patient Demographics
 
−
#Language Preferences.
 
−
#Contact Information for Family and Friends.
 
−
#Active Medication Problem Lists
 
−
#Allergies.
 
−
#Immunization Records
 
−
#Lab Results from the past year.
 
−
#Medications prescribed in the past year.
 
−
#Clinic Visit Information with diagnoses and procedures in the past year.
 
−
#Hospitalizations with diagnoses and procedures.
 
−
#Most recent EKG's and chest x-rays-both readings and images.
 
−
 
−
These drives offer many advantages.
 
−
#They are completely portable and can be with a patient at all times.
 
−
#They can be read by anyone with the appropriate password.
 
−
#They are upgradable with minimal effort.
 
−
#Patients need no computer expertise. They simply have to remember a password.
 
−
#If a patient is unable to give any information, a family member is able to provide a password if this has been planned beforehand.
 
−
 
−
Security however remains a concern. They must be encoded adequately with secure passwords. In addition, they can be easily lost or stolen.
 
−
Biometrics such as fingerprint identification could be used with some of these devices possibly along with an alternative digital password.
 
−
 
−
== Benefits to patients, providers, purchasers and payers of health care from PHR ==
 
−
 
−
# Patients having greater access to their own medical information, allowing them to be actively involved in the management of their disease.
 
−
# An ongoing communication between patients and physicians, which promotes a real time response from the providers in management of acute and chronic disease.
 
−
# Providers having greater access to data that could help them in their decision making process.
 
−
# Patients and physicians are working together to manage patients’ illnesses, including to reduce pain, to improve functional outcome, and to promote adherence to medications.
 
−
# Electronic communication between patients and providers free or limit telephone and face-to-face communication that at times interfere with the workflow of the providers.
 
−
# Payers and purchasers of health care could potentially benefit from lower costs, including lower medication and chronic disease management costs.
 
−
# A study by [[Going Mobile: How Mobile Personal Health Records Can Improve Health Care During Emergencies|Bouri et al]] speaks about PHRs in mobile format (mPHRs) which can be used during emergencies and natural disasters when EHR's are inaccessible. During Public Health emergencies health care providers who are unfamiliar with the patient can have instant access to a patient’s medical history.
 
−
 
−
References: 1.A New Health System for the twenty-first Century. Washington. National Academies Press;2001. Crossing the Quality Chasm.
 
−
2. Kim E,Modi S, Fang D, Soh CB, Kim Y. Web-based Personal-Centered Electronic Health Record for Elderly Population; D2H2 Conference, 2005.
 
−
3.Tan PC, Ash JS, Sands DZ. Personal health records: definitions, benefits, and strategies for overcoming barriers to adoption. JAMIA. 2006 Mar-Apr; 13(2): 121-6. Epub 2005 Dec 15.
 
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4. Shetty, R. Portable Digital Personal Health Record: To Bridge the Digital gap in Medical Information Storafe of Individuals with PErsonal Health Records in Flash Drives. The Internet Journal of Health. 2007 Vol 5 (2)
 
−
5.Cushman, R. Primer: Data Protection and the Personal Health Record. UM-Miller School of Medicine Project Health Design ELSI Team, University of Miami.
 
−
 
−
== Challenges ==
 
−
 
−
In passing the [[ARRA|Health Information Technology for Economic and Clinical Health (HITECH) Act]], which was part of the American Recovery and Reinvestment Act of 2009, Congress focused on the promotion of the “meaningful use” adaptation of electronic health records (EHRs), and on health information exchange (HIE).4,5 HITECH Act of 2009 made no mention of patient health records (PHR).4,5  In 2009 AHIMA, in “AHIMA Written and Oral Testimony at the NCVHs Privacy, Confidentiality & Security Subcommittee Hearing on Personal Health Records noted that there is a real concern for the viability of PHR, and its ability to take off and continue to strive in health care due to privacy, confidentiality and security concerns.4
 
−
 
−
# Whether patients should have the ability to modify professionally sourced data.3,4,6,7,8
 
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−
The issue is one of a balance between the patient’s rights to privacy and confidentiality and the need of the providers for data integrity.1 This is a major concern with PHRs, and is one that is highly disputed. Some systems ,like Indivo, provide full privacy and security to the patient. The patient can completely control who can read, write or modify his or her records.5 In other systems, such as those used in the military health system's personal health record pilot with Microsoft HealthVault and Google Health, the issue is handled by assigning an administrative to make changes.8
 
−
 
−
# The ability of patients to withhold certain medical information from their providers (a privacy issue) may at times be in conflict with patient safety.8
 
−
 
−
The ability of patients to determine which medical information to share with their providers may result in the providers making clinical decisions based on incomplete information, potentially causing harm to patients. This may create a conflict between the patients need to control their information and their safety.8
 
−
   
 
−
# Should providers be able to withhold extremely sensitive information from PHR, or at the very least, institute a waiting period in reporting? 8
 
−
 
−
Should certain sensitive information, such as lab results related to sexually transmitted diseases findings, pregnancy results, and positive cancer findings, not be released into the PHR, and instead, be reported to the patient in person?</nowiki>Other challenges commonly associated with PHRs, include the following: Should the entire Problem List be shared? 3 Should the entire Medication and Allergy Lists be shared? 3 Should all laboratory and diagnostic test results be shared with the patient? 3,9 Should clinical notes be shared with the patient? 3 Should minors be able to have their own private PHR, and should patients be able to share access to their PHR via proxies? 3,10,11
 
  
 +
There are many more potential use-cases for blockchain technology within healthcare, and undoubtedly we will continue to see development in this area in coming years. In 2016, a consortium of sponsors led by [https://gem.co/ Gem] (Whitepaper)<ref>Wood C, Winton B, Carter K, Benkert S, Dodd L, Bradley J, et al. How Blockchain Technology Can Enhance Ehr Operability [Internet]. 2016. Available from: http://research.ark-invest.com/blockchain-and-healthcare</ref> held the first healthcare oriented blockchain conference, [https://godistributed.com/health Distributed: Health] in Nashville, TN. Similarly, the Office of the National Coordinator (ONC) Tech Lab had issued a Blockchain Challenge in July, 2016.<ref>https://oncprojectracking.healthit.gov/wiki/display/TechLabI/Blockchain+Challenge+on+ONC+Tech+Lab</ref>
 +
* The list of submissions and awards can be found [https://oncprojectracking.healthit.gov/wiki/display/TechLabI/Blockchain+Challenge+on+ONC+Tech+Lab here]
  
 +
As the healthcare blockchain community grows, gatherings such as these will likely increase and blockchain technologies will increasingly be introduced at major medical conferences.
  
 
== References ==
 
== References ==
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<references />
  
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Submitted by Nhat Pham
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[[Category: BMI512-FALL-18]]
  
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Submitted by Sandeep Regmi
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[[Category: BMI512-FALL-18]]
  
 
Submitted by Ben Orwoll
 
Submitted by Ben Orwoll
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[[Category: BMI512-FALL-16]]
  
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[[Category:BMI512-FALL-16]]
 
 
[[Category: Reviews]]
 
[[Category: Reviews]]
 
[[Category: Other Technologies]]
 
[[Category: Other Technologies]]

Latest revision as of 03:17, 19 October 2018

The blockchain is an idea centered around the concept of a secure, digital ledger system that provides a system for efficient, auditable transactions of almost any type between entities [1]. All information related to blockchain transactions is at once both independently verifiable by all (even outside) parties as correct and also inscrutable to entities without explicit permission. The first and probably most well-known implementation of blockchain technology is Bitcoin [2], but there has been a massive expansion of blockchain use-cases since Bitcoin's initial introduction.


What is the Blockchain?

First, it should be clear that there is no one blockchain to rule them all. "The Blockchain," as it is often referred, really is a concept of a series (chain) of interrelated sets (blocks) of encrypted information. Hence a chain of blocks, or blockchain. There are many such blockchains in existence, and one could choose to do transactions on any one of them or create a new blockchain.


An important aspect of most blockchains is that they are designed to be maintained on a distributed network of multiple nodes. Each node holds a complete copy of the blockchain and adds each sequential new block as it is created. This system allows every transaction on the blockchain to be verified by any or all of the nodes in the network, and also makes it very difficult for the information held in the blockchain to become lost or unavailable if any one or even most of the nodes go offline.


Transactions that are set to be added to the blockchain are added to the newest block as soon as it is created. This makes the continued existence of the blockchain dependent on the creation of new blocks. There are several main methods for the creation of new blocks on the network, and the choice of method depends somewhat on the purpose of the blockchain in question. Bitcoin, the first cryptocurrency, uses a method called Proof of Work System (Wikipedia):

  • In the traditional Proof of Work System, each block validator, or "miner," competes to validate the block by processing a task. The winner is the first person to complete this task. The chance of completion of the task is random based on a hash function, but increases with the more "work" a person puts into the task. The system can automatically vary the difficulty of the task to limit the speed of block generation. The winner is credited for his/her work by a small amount of currency.


The blockchain has moved beyond simply processing transactions of cryptocurrency such as Bitcoin. Any data that can be encoded into a cryptographic hash can be added to a blockchain. Various different ideas have been proposed, and I will not attempt to list them here, but they are wide ranging. Melanie Swan predicts three phases of blockchain adoption: Blockchain 1.0, 2.0, and 3.0[3]. Blockchain 1.0 manifested as online currency. Blockchain 2.0 is the near future, where blockchain is used to keep track of contracts, financial records, public records, and ownership of property. Blockchain 3.0 will be applied into science, medicine and education.


Blockchain Development Groups

Certainly a non-exhaustive list . . .

Blockchain Use Cases

Cryptocurrency

Bitcoin (BTC) was the first cryptocurrency based on the blockchain and was developed by someone calling himself (or herself) Satoshi Nakamoto. The protocol was introduced in 2008 after the publication of a white paper[2] describing the algorithm and the mechanisms for generation and distribution of BTC. At this point there are hundreds of cryptocurrencies in circulation according to Wikipedia, many of which are based on the Bitcoin blockchain, but only a few have gone into widespread use[4].

Smart Contracts

One of the major potential functions of blockchain technology is through the creation of smart contracts. Various components of contracts, including proof of the involved parties, requirements for completion, and actions upon completion of the contract can be encoded in blocks. These can then be added to a blockchain and become available for independent verification, which can even lead to automatic processing of contracts when their requirements have been fulfilled.

Smart contracts are scripts which have various rules and logic that automatically execute when those rules are met. Smart contracts allow heavily automated workflows between transacting parties in the network while maintaining anonymity. Once the contract has been executed, one can take custody over assets or pre-defined payments can be issued. [5] They are importantly different in the sense that they are stored on a distributed network and they can be verified as true without knowledge of the contract specifications [6].

The Ethereum Project was one of the first to introduce the concept of smart contracts using their alternative blockchain and currency token, ether.

Securities Exchanges and Finance

One of the hottest arenas for blockchain development currently is in the financial markets, an extension of the original cryptocurrency use cases for the blockchain. Multiple stock markets and other financial firms have initiated investigations and pilot projects into the feasibility and utility of the blockchain for contracts and tracking of financial instruments. NASDAQ has been one of the first major markets to put blockchain technology into use, and has released some information on its implementation, called Linq [7][8]. The cryptocurrency website Coindesk has also produced a list of 10 exchanges using or investigating blockchain technologies[9].


Additionally, financial firms such as Visa have been experimenting with the blockchain for keeping track of transactions as well as with proof of concept applications such as remittance[10].

Advantages and Disadvantages of Blockchain

Blockchain is a novel concept and is being explored in various sectors. While there may be several applications and limitations of this technology in future, some of them are highlighted below[11]:

Pros:

  1. Distributed: There is no single owner of the database. As anyone can contribute and be a part of the network, the risks of data tampering and fraud are minimal. As Nakamoto [2] mentioned, as long as the majority of nodes are honest, a random attacker would not be able to alter the history.
  2. Trustless: As every node in the network will have a copy of the blockchain and they verify the transactions independently. Hence, this system allows transaction even if the parties don't trust each other.
  3. Immutable: Once the transaction is verified and embedded in the blockchain, it is almost impossible to undo it, and the complexity increases with time as more blocks are added downstream. This allows keeping a track of accurate events that occurred through the history.
  4. Decentralized: There is no middleman like banks or data owners. This helps avoid manipulation of the market by the owners.


Cons:

  1. Waste of resources: As several nodes are running and utilizing a huge amount of computing power and electricity to verify and maintain the blockchain, there is more than required redundancy.
  2. Higher cost for less value: With time, the use of network increases and the complexity of the hashing algorithm also increases. Hence, more resources are required for the same amount of work. This increases the cost of work and transactions gets slower, as miners prioritize the transactions with higher incentives causing a backlog the transactions with smaller values.
  3. Difficulty to keep up with the size of the block: As the size continues to grow along with the complexity to solve the calculation, new nodes with smaller computing power will have difficulty joining the network and likewise, the older and slower nodes will gradually fade with decreasing incentive for the work. Hence, like Darwin’s theory of the "survival of the fittest", a few larger nodes will dominate the network creating more and more centralization of the system.
  4. Speculative market: Due to the lack of proper regulation of this system, the market is subject to a great volatility and thus making it risky for investors.
  5. Immutable smart contracts: As there are clear advantages of having permanent and immutable records, at the same time, there is a bitter flipside to this. For example, if there is a flaw with code that can compromise the system, it is also irreparable and creates the opportunity for the attackers to exploit the same flaw repetitively in future. As time progresses, the capability of repairing the error will be even more complex.


Possible Solutions:

  • The issues with resource wastefulness and diminishing return of investment are mainly an issue with Proof-of-Work Systems, and can be improved with new blockchain innovations such as Proof of Stake (Bitcoin Wiki) or blockchain scaling[12]
    • There are some issues with the original Proof of Work that Satoshi created: 1) it was very resource intensive and 2) as the bitcoin reward becomes harder to obtain as the blockchain grows, there is less incentive to mine. With fewer miners come fewer validators of the block which could allow malicious actors to introduce fake block into the chain. An alternative to Proof of Work is Proof of Stake[13]. In Proof of Stake, the amount of work a user can do depends on their "wealth," or the amount of currency they own (if they own 1% of the currency, they can mine 1% of the block). In order for someone to manipulate the block, they have to own more than a majority of the currency (51% or more), making successful attacks on the blockchain very expensive. Furthermore, the attack would devalue the currency, resulting in a big hit to the attacker.
    • Currently, all computers that participate in mining a blockchain process every transaction. This is very slow and resource wasteful. A solution to this is to calculate how many computers will be needed to validate a new block, and give the task of verifying a transaction to those computers. This will allow parallel processing (scaling) of "blocks" and speed up transactions. At this point, the details behind how to manage this division of tasks without compromising security still being worked out.

Potential Use Cases in Healthcare

Though there has yet to be a breakthrough report or use-case for blockchain technology in healthcare, there are many potential ways that the blockchain could be implemented within the current healthcare structure. Any list will likely be incomplete, but these examples represent some of the published and available literature on blockchain implementations in health.

Health Information Exchange (HIE)

One major area that blockchains may be able to facilitate is the secure access to and communication of patient health records between individuals and institutions. There have been multiple white papers published on the topic, including groups from the Mayo Clinic [14] and MIT [15] who described a system for patient information exchange based on blockchain technology that would allow patient-controlled access to records across institutions using HL7 Fast Healthcare Interoperability Resources (FHIR), JSON, or other encoding system. In these models the actual health care data are not encoded in the blockchain, but are merely references pointing to where the data reside, such as at institutions or in a "data lake" [16]. Similarly, a group out of China described an app called Healthcare Data Gateway (HGD) that allows patients to view and directly control rule-based access to their health records with a smart phone interface and authentication provided by a blockchain network [17]. These ideas support the concept of patient-owned medical data, and would have the effect of decentralization of medical records in ways that are as yet undetermined.

Health Research Integrity

Academic research is a major driver of advances in health care, but in the setting of limited funding and publication pressures on researchers significant concerns have been raised regarding research integrity[18]. Organizations such as ClinicalTrials.gov and others have been developed to help drive researchers to define endpoints and analysis prior to conducting clinical trials and other studies. As it represents an immutable, verifiable record of events and transactions, the blockchain has been proposed as a potential decentralized resources for helping to ensure biomedical research integrity. Benjamin Carlisle[19], followed by several researchers from the UK[20], proposed in 2014 that researchers could use the blockchain to record pre-specified aspects of their projects, including the study design, analysis plan, and data structure, among others, which could later be verified by consumers of the literature to decrease bias that may be introduced in post-hoc analysis[21]. The blockchain also offers the potential ability to verify the integrity of actual research data and analysis by outside observers, even if the data themselves are not made publicly available. These types of implementations may lead to improvements in both the integrity of biomedical research as well as bolster public trust in medical research.

Personal Health Records

This concept dovetails with the idea of HIE using the blockchain, but focuses more on the secure maintenance of a personal health record (PHR) by patients. No production PHR has been released based on this technology, but concepts such as MedVault [22] use alternative blockchains such as Colu to store patient data directly on the blockchain. Others such as eHealthWallet have also developed prototype PHRs based on the blockchain. Patients could then share or authorize doctors and other health entities to access and modify their data.

The majority of the proposals leverage blockchain’s ability to maintain an immutable record to place control of patient’s health record into their hand by allowing them to grant and revoke access to their medical records according to their preference[23][24].

  • In a traditional system, patient’s health record is kept and maintained by a health care organization (e.g. hospital, clinic, etc.). Information can be freely shared between the organization and a Regional Health Information Organization (RHIO) or another organization that has a business agreement with the originating institution. If there is no business agreement between the institutions, one-off requests can be made, but this will take time and delay care.
  • As Meaningful Use Stage 3 is being implemented at health care organizations, there has been a push to create patient-facing application programming interfaces (APIs) that allow patient to directly retrieve their record from the institution and share it with the provider as needed.
  • A blockchain-enabled smart contracts controlled by the patient can be used to authorize direct sharing of medical record between institutions. Patient can specify the subset of the record to be shared or set an expiration date on the authorization.

Gordon et al. suggested five features of block chain that allow for successful patient-driven interoperability[25]:

  • Digital access rules: The blockchain-enabled digital access rule is centralized, which makes it accessible by multiple institutions, while facilitating editing of the rules by the patient at any moment via a smart phone-based or web-based application
  • Data aggregation: Patient could also aggregate their data (or metadata) across institutions to a blockchain or another secured location using the digital access rule, thus creating a complete record of their health
  • Data liquidity: Because the change in digital access rules will take effect as soon as the patient (or legal representative) approves it, data can be share rapidly to the requesting institution, allowing access to time-sensitive information such as allergies, “code status,” etc.
  • Patient identity: Even though there is no national patient identifier, institutions can use the blockchain-assigned individual’s public key and match it with their local identifier to start sharing data across systems
  • Data immutability: Since all changes made to the blockchain is recorded and immutable, the risk of loss is minimized, and the record can be audited at any time.

There are several limitations of the current state of technologies for blockchain-based personal health records:

  • The first concern with block chain is its inability to handle the transaction volume of clinical data. Blockchain is great at keeping a record of changes to a small amount of data (such as account balance, owner’s identity, etc.). However, it is not economically practical to store a large amount of data on the blockchain due to cost associated with creating a very large ledger to store this information and to perform proof-of-work on this ledger. Proposed solutions include:
    • Validate data using a different approach to consensus such as proof-of-stake.
    • Store a summary of, instead of a complete clinical report.
    • Patient’s data can be stored on a permissioned (private) regional blockchains that are built to handle large transaction volumes without time-intensive validation.
  • A second limitation of blockchain is the lack of privacy and security. Even though the identifier on the blockchain is the cryptographically generated public key, this is only pseudonymous, as patient can still be identified by matching for other basic demographic information, and once the public key has been linked to the patient, their activity on the blockchain can be tracked. A few solutions to this problem has been proposed:
    • Use permissioned (member-only) blockchain to avoid public exposure.
    • Basic demographic information stored on a block chain can also be encrypted to prevent access.
    • Store sensitive data off-chain, with on-chain data focusing on granting permission to access requested data using pointers and metadata. This would also allow patients to assign different access rule for different users of their data
  • Since the focus of many blockchain-based projects is on patient-controlled health care data, it necessitates more patient participation than the traditional, institution-based paradigm. They must be able to assign certain permissions for different institutions that request access.
    • Having a patient-friendly “app” to manage public keys and permissions will become very important to get more buy-in from patients.
    • Patient will also need to keep track of their password to gain access to their private key in order to make changes to the block chain. There will need to be a mechanism for recovering lost password when this occurs.
  • The largest barrier to widespread adoption of blockchain in healthcare deals with the issue of incentives. Meaningful Use stage 3 requires implementation of patient-facing API, but this does not entail handling access control of healthcare record to patient. Institution has little incentive to pay for the cost of setting up a blockchain just to give patient more control even though this will improve interoperability. To overcome this, a few proposals have been made:
    • Expand federal incentives to patient-controlled medical record.
    • Researchers can be incentivized to pay for the setup of these blockchains by gaining access to patient anonymized data for research purposes.

Storage of Health Care Data

Most of the previous examples use the blockchain not as a direct data storage medium, but instead as a secure reference point for identities, access, and data locations. At least one group from a company called Tierion, which partners with the Philips Blockchain Lab , has produced a concept called Chainpoint[26], which proposes to use a Proof of Existence concept and Merkle Roots[27] to efficiently store actual patient records on the blockchain without imposing excessive transaction demands on the system.

Billing and Claims Adjudication

Blockchain system can help reduce administrative costs and time while automating claims adjudication and payment processing using smart contracts. For example - a smart contract is set up between payer or insurance company, provider, and patient such that when the patient sees a provider, or if a procedure is done, an entry is recorded in the blockchain. Based on the criteria set, the contract can automatically issue reimbursement from the payer as well as co-pay from the patient without having to wait for the insurance approval.[28]

Drug Supply Chain and Prescription Management

Counterfeit drugs are a major problem especially in the developing country where it is estimated that about 1 in 10 medical products are counterfeit [29]. Ensuring the integrity of the drug and maintaining a robust audit trail is a must to ensure patient safety. Similarly, this platform can be used in prescription drug management and track history and authenticate prescriptions using smart-contracts.

Few Examples of Current Use Cases and Future Development

  • MedRec- it is based on Ethereum platform and focuses on medical data management using smart contracts like managing permissions and authentication processes, data sharing in an interoperable environment between healthcare systems and maintaining an audit log. [30]
  • Guardtime- also focuses on medical data management and has partnered with e-Health authority of Estonia to secure the country's database of health records [31]. Also, recently, MyPCR smartphone platform from Guardtime has partnered with Instant Access Medical and Healthcare Gateway in the UK for patient health data management and verification of medication adherence. [32]
  • Blockchain Health- created for healthcare research data management where users can individually authorize the release of their health information to researchers as well as track the use of their data. [33]
  • BlockMedx- it is a startup company which intends to use the blockchain platform to transmit DEA controlled drug prescriptions from physicians to pharmacies and then to patients securely. [34]
  • MediLedger- another pharmaceutical supply chain management startup company who has partnered with several drug manufacturers and aims to provide an open, secure and interoperable network. [35]
  • Drug and Pharmacy Verification - VeriPharm has developed a proof of concept that would help track and verify pharmaceuticals from the raw materials to the final product administered to patients.
  • Care Coordination - Projects such as simplyvitahlth are geared toward coordinating care between multiple providers and at different institutions to ensure that complex care pathways are being followed appropriately.


There are many more potential use-cases for blockchain technology within healthcare, and undoubtedly we will continue to see development in this area in coming years. In 2016, a consortium of sponsors led by Gem (Whitepaper)[36] held the first healthcare oriented blockchain conference, Distributed: Health in Nashville, TN. Similarly, the Office of the National Coordinator (ONC) Tech Lab had issued a Blockchain Challenge in July, 2016.[37]

  • The list of submissions and awards can be found here

As the healthcare blockchain community grows, gatherings such as these will likely increase and blockchain technologies will increasingly be introduced at major medical conferences.

References

  1. ↑ Tapscott D, Tapscott A. Blockchain Revolution: How the Technology Behind Bitcoin Is Changing Money, Business, and the World. United States: Portfolio; 2016. 1-368 p.
  2. ↑ 2.0 2.1 2.2 Nakamoto S. Bitcoin: A Peer-to-Peer Electronic Cash System. WwwBitcoinOrg [Internet]. 2008;9. Available from: https://bitcoin.org/bitcoin.pdf
  3. ↑ Swan, M. (2015). Blockchain: Blueprint for a new economy: " O'Reilly Media, Inc."
  4. ↑ https://en.wikipedia.org/wiki/List_of_cryptocurrencies
  5. ↑ Christidis, K & Devetsikiotis, M. (2016, May 10). Blockchains and Smart Contracts for the Internet of Things. IEEE Access, 4, 2292-2303. doi: 10.1109/ACCESS.2016.2566339
  6. ↑ https://bitsonblocks.net/2016/02/01/a-gentle-introduction-to-smart-contracts/
  7. ↑ http://ir.nasdaq.com/releasedetail.cfm?releaseid=948326
  8. ↑ http://www.coindesk.com/hands-on-with-linq-nasdaqs-private-markets-blockchain-project/
  9. ↑ http://www.coindesk.com/10-stock-exchanges-blockchain/
  10. ↑ http://www.coindesk.com/hands-on-with-visa-europes-bitcoin-remittance-app/
  11. ↑ Fauvel, W. (2017, August 11). Blockchain Advantage and Disadvantages. Medium. Retrieved from: https://medium.com/nudjed/blockchain-advantage-and-disadvantages-e76dfde3bbc0
  12. ↑ Croman, Kyle, et al. "On scaling decentralized blockchains." International Conference on Financial Cryptography and Data Security. Springer, Berlin, Heidelberg, 2016.
  13. ↑ Siim, Janno. "Proof-of-Stake."
  14. ↑ Peterson K, Deeduvanu R, Kanjamala P, Boles K. A Blockchain-Based Approach to Health Information Exchange Networks. (1):1–10.
  15. ↑ Ekblaw A, Azaria A, Halamka JD, Lippman A, Original I, Vieira T. A Case Study for Blockchain in Healthcare: “ MedRec ” prototype for electronic health records and medical research data MedRec: Using Blockchain for Medical Data Access and Permission Management [Internet]. 2016. Available from: https://www.healthit.gov/sites/default/files/5-56-onc_blockchainchallenge_mitwhitepaper.pdf
  16. ↑ Linn LA, Koo MB. Blockchain For Health Data and Its Potential Use in Health IT and Health Care Related Research. 2014;1–10.
  17. ↑ Yue X, Wang H, Jin D, Li M, Jiang W. Healthcare Data Gateways: Found Healthcare Intelligence on Blockchain with Novel Privacy Risk Control. J Med Syst [Internet]. 2016 Oct;40(10):218. Available from: http://dx.doi.org/10.1007/s10916-016-0574-6
  18. ↑ Titus SL, Wells J a, Rhoades LJ. Repairing research integrity. Nature [Internet]. 2008 Jun 19;453(7198):980–2. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18563131
  19. ↑ Carlisle BG. Proof of prespecified endpoints in medical research with the bitcoin blockchain [Internet]. 2014. Available from: http://www.bgcarlisle.com/blog/2014/08/25/proof-of-prespecified-endpoints-in-medical-research-with-the-bitcoin-blockchain/
  20. ↑ Irving G, Holden J. How blockchain-timestamped protocols could improve the trustworthiness of medical science. F1000Research [Internet]. 2016;5:222. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866630/
  21. ↑ Slade E, Drysdale H, Goldacre B, COMPare Team. Discrepancies Between Prespecified and Reported Outcomes. Ann Intern Med [Internet]. 2016 Mar 1;164(5):374. Available from: http://www.ncbi.nlm.nih.gov/pubmed/26720309
  22. ↑ Baxendale G. Can Blockchain Revolutionise EPRs? [Internet]. Vol. 58, ITNOW. 2016. p. 38–9. Available from: http://itnow.oxfordjournals.org/lookup/doi/10.1093/itnow/bww017
  23. ↑ Gordon, W. J., & Catalini, C. (2018). Blockchain Technology for Healthcare: Facilitating the Transition to Patient-Driven Interoperability. Comput Struct Biotechnol J, 16, 224-230
  24. ↑ Yue, X., Wang, H., Jin, D., Li, M., & Jiang, W. (2016). Healthcare Data Gateways: Found Healthcare Intelligence on Blockchain with Novel Privacy Risk Control. J Med Syst, 40(10), 218. doi:10.1007/s10916-016-0574-6
  25. ↑ Gordon, W. J., & Catalini, C. (2018). Blockchain Technology for Healthcare: Facilitating the Transition to Patient-Driven Interoperability. Comput Struct Biotechnol J, 16, 224-230
  26. ↑ Vaughan AW, Bukowski J, Wilkinson S, Sporny CM, Shea R, Allen C, et al. Chainpoint: A scalable protocol for anchoring data in the blockchain and generating blockchain receipts [Internet]. 2016. Available from: https://tierion.com/chainpoint
  27. ↑ Merkle RC. PROTOCOLS FOR PUBUC KEY CRYPTOSYSTEMS. In: IEEE Symposium on Security and Privacy [Internet]. 1980. p. 122–34. Available from: http://www.merkle.com/papers/Protocols.pdf
  28. ↑ Srinivasan, P. (2017, November 9). Healthcare Blockchain: How Smart Contracts Could Revolutionize Care Delivery. Prolifics. Retrieved from: https://www.prolifics.com/blog/healthcare-blockchain-how-smart-contracts-could-revolutionize-care-delivery
  29. ↑ WHO. (2017, November 28). 1 in 10 medical products in developing countries is substandard or falsified. Retrieved from: http://www.who.int/en/news-room/detail/28-11-2017-1-in-10-medical-products-in-developing-countries-is-substandard-or-falsified
  30. ↑ Azaria, A., Ekblaw, A., Vieira, T., & Lippman, A. (2016, August 22-24). MedRec: Using Blockchain for Medical Data Access and Permission Management. 2016 2nd International Conference on Open and Big Data (OBD). doi:10.1109/obd.2016.11
  31. ↑ Ruubel M. (2016, February 12). Estonian eHealth Authority Partners with Guardtime to Accelerate Transparency and Auditability in Health Care. Retrieved from: https://guardtime.com/blog/estonian-ehealth-partners-guardtime-blockchain-based-transparency
  32. ↑ Ruubel M. (2018, June 20). World’s first blockchain-supported Personal Care Record Platform launched by Guardtime and partners to up to 30 million NHS patients in the UK. Retrieved from: https://guardtime.com/blog/world-s-first-blockchain-supported-personal-care-record-platform-launched-by-guardtime-and-partners
  33. ↑ BlockchainHealth. (2016). Blockchain for health research. Retrieved from: https://blockchainhealth.co/
  34. ↑ BlockMedx. (2018). Retrieved from: https://blockmedx.com/en/
  35. ↑ MediLedger. (2018). The MediLedger Project. Retrieved from: https://mediledger.com/
  36. ↑ Wood C, Winton B, Carter K, Benkert S, Dodd L, Bradley J, et al. How Blockchain Technology Can Enhance Ehr Operability [Internet]. 2016. Available from: http://research.ark-invest.com/blockchain-and-healthcare
  37. ↑ https://oncprojectracking.healthit.gov/wiki/display/TechLabI/Blockchain+Challenge+on+ONC+Tech+Lab

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