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Lau","url":"https:\/\/medwave.io\/author\/admin-2\/","identifier":2,"image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c316763f6818380164c3414fc4575167bcffddaaedbc31902e4e2c7a44540392?s=96&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c316763f6818380164c3414fc4575167bcffddaaedbc31902e4e2c7a44540392?s=96&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Medwave Billing & Credentialing","logo":{"@type":"ImageObject","@id":"https:\/\/medwave.io\/wp-content\/uploads\/2017\/12\/medwave-pittsburgh-medical-billing-400x400.png","url":"https:\/\/medwave.io\/wp-content\/uploads\/2017\/12\/medwave-pittsburgh-medical-billing-400x400.png","width":200,"height":200}},"image":{"@type":"ImageObject","@id":"https:\/\/medwave.io\/wp-content\/uploads\/2024\/02\/hl7-versus-fhir.jpg","url":"https:\/\/medwave.io\/wp-content\/uploads\/2024\/02\/hl7-versus-fhir.jpg","height":300,"width":620},"url":"https:\/\/medwave.io\/2024\/02\/hl7-vs-fhir-the-key-differences\/","about":["Articles","Fast Healthcare Interoperability Resources","FHIR Adoption","FHIR API","FHIR APIs","FHIR Bundles","Health Level 7","HL7","HL7 API","HL7 FHIR","HL7 Interface","HL7 messaging","HL7 Standard","HL7 v2.x","HL7 vs FHIR","HTTP Methods","JSON","JSON\/XML","RESTful web APIs","XML"],"wordCount":2635,"keywords":["API","Fast Healthcare Interoperability Resources","FHIR","FHIR Adoption","FHIR APIs","FHIR Bundles","GET {serverURL}","Health Level 7","HL7 v2.x","HL7 vs FHIR","HTTP Methods","JSON","JSON\/XML","POST {serverURL}","PUT {serverURL}","RESTful APIs","RESTful web APIs","XML"],"articleBody":"Health information exchange (HIE) is crucial for improving healthcare quality, safety, efficiency, and reducing costs. Two major standards for exchanging healthcare information electronically are Health Level 7 (HL7) and Fast Healthcare Interoperability Resources (FHIR). Both play important roles in healthcare interoperability, but have key differences.We take an in-depth look at HL7 and FHIR, their history, features, similarities and differences, and future outlooks.What is HL7?HL7 stands for Health Level Seven, referring to the seventh level of the International Organization for Standardization\u2019s (ISO) communications model for Open Systems Interconnection (OSI). HL7 is a set of standards for exchanging electronic health information between software applications used by various healthcare organizations.HL7 standards apply to the application layer, which is \u201cLevel 7\u201d in the OSI model. The application layer interfaces directly to and performs common application services for the application processes. Application layer protocols include file transfer, email, and remote file access.The first version of HL7 was published in 1987 by a group of large healthcare organizations who met at the University of Pennsylvania. The standard was created to exchange clinical data and integrate independent healthcare systems. HL7 quickly gained adoption for allowing healthcare providers to exchange patient clinical and administrative data electronically.HL7 standards pertain to both the syntax (structure and format) and semantics (meaning) of messages exchanged between systems. An HL7 message has a series of segments in a defined sequence, each containing one or more composites which have data fields.For example, a message may contain patient name, gender, birth date, and other information. HL7 specifies the order of segments, the structure of each segment, data types, and code systems to be used. HL7 v2.x is the most commonly used HL7 version today.What is FHIR?FHIR (Fast Healthcare Interoperability Resources) is the newest draft standard for exchanging electronic health records, published in 2014 by Health Level Seven International (HL7).The purpose of FHIR is to define flexible, lightweight data formats and open application programming interfaces (APIs) for exchanging electronic medical records between different systems. The FHIR standard builds on previous HL7 standards, but is intended to be faster and easier to implement.Some key features of FHIR include:Modular components called \u201cResources\u201d that can be assembled into messages and documentsResources have common structures, behaviors, and APIs enabling reuseSupport for JSON and XML data formatsRESTful APIs using HTTP and REST principlesUse of modern web standards and architecture principlesFHIR was created by HL7 and the open-source community to address limitations of older HL7 versions. It aims to simplify implementation, accelerate interoperability between systems, and enable innovation on top of the standard.Brief History of HL7 and FHIRHL7’s first standards were developed in the late 1980s to exchange clinical data between independent departmental systems. By the 1990s, HL7 v2.x messaging was established as the dominant standard for healthcare interfaces. However, implementing HL7 v2.x interfaces was complex and costly.In the 2000s, the focus shifted to developing electronic health record (EHR) standards and promoting EHR adoption. HL7 v3 messaging was introduced in 2005 as the next-generation standard but failed to gain significant traction due to its complexity.By 2010, the industry had rallied around the idea of simple web APIs for EHR interoperability. In 2014, HL7 published the FHIR standard based on web APIs and gained broad interest. FHIR is now quickly becoming the leading standard for healthcare interoperability.HL7 v2.x is still widely used today, but FHIR adoption is rapidly accelerating as vendors modernize their offerings. FHIR combines the best lessons learned from previous standards while leveraging modern web technologies.Key Similarities Between HL7 and FHIRAlthough HL7 and FHIR were developed during different eras, they have some important similarities:Developed by Health Level Seven (HL7) as standards for exchanging electronic health informationAllow encoding of healthcare data into standardized electronic messages that can be exchanged between health information systemsSeek to allow healthcare systems to communicate and exchange data, promoting integration and interoperabilityHandle patient health information like laboratory tests, medical reports, diagnoses, medications, etc.Aim to improve efficiency, quality, and continuity of care across the health systemDefine both syntax (structure) and semantics (meaning) to facilitate data exchangeHave extensible code systems to send and interpret coded data elementsAre ANSI-accredited standards approved through a consensus processWidely adopted internationally for healthcare data integration and exchangeBoth standards serve the overall goal of integrating disconnected health systems to enable data exchange for improved healthcare delivery.Key Differences Between HL7 and FHIRWhile HL7 and FHIR share some high-level goals, they differ significantly in their technical approach:Messaging Structure – HL7 v2.x uses delimited segments and messages. FHIR uses resources with common formats, behaviors, and RESTful APIs. FHIR has greater flexibility.Ease of Use – HL7 v2.x has rigid specifications requiring custom integration. FHIR aims for simplicity using modern web standards and a modular framework.Implementation – HL7 v2.x requires specialized interfaces and custom code. FHIR uses modern RESTful APIs for rapid app development and system access.Tooling – HL7 v2.x has limited off-the-shelf software and tooling support. FHIR enables use of web dev tools, frameworks, and libraries.Data Formats – HL7 v2.x uses ER7 for encoding. FHIR uses XML, JSON, RDF for broader compatibility.Architecture – HL7 v2.x follows tightly coupled point-to-point messaging. FHIR emphasizes decentralized access and a loosely coupled publish-subscribe model.Maturity – HL7 v2.x is a mature standard with decades of implementations. As a newer standard, FHIR has less production experience but strong momentum.Focus – HL7 v2.x enables administrative, financial, and clinical data exchange. FHIR focuses mainly on the exchange of clinical content and patient data.Adoption – HL7 v2.x has near-universal adoption for legacy interfaces. FHIR adoption is rapidly growing for newer interoperability needs.To summarize, FHIR offers major improvements in flexibility, ease of use, scalability, and developer experience compared to prior HL7 standards. Yet, HL7 v2 retains extensive legacy use. The two standards co-exist with FHIR addressing modern requirements.FHIR Resources ExplainedResources are the basic building blocks of FHIR. Resources represent granular clinical or administrative concepts that can be assembled into messages or documents.Some examples of FHIR resources:Patient – Demographics, contact info, relationshipsObservation – Clinical measurement, finding, assessmentProcedure – Healthcare intervention\/service providedCondition – Clinical diagnosis identified from observationsMedication – Medicine or vaccine administered to a patientQuestionnaire – A set of questions for gathering dataDiagnostic Report – Interpretation of diagnostic tests and resultsAll resources share a common framework with set of features:JSON\/XML representationUnique canonical URL for each resourceHuman-readable terminology for data elementsCommon metadata like id, version, lastUpdatedReferences to link resources togetherAPIs for CRUD operationsThis consistent structure allows FHIR resources to be understood by different systems and enables modular resource reuse. Resources can be aggregated to represent complex clinical concepts or assembled into parcels of data called “bundles“.The APIs allow resources to be created, retrieved, updated, deleted, searched, versioned and processed according to common patterns. Implementations can leverage off-the-shelf tooling and libraries instead of needing specialized interfaces.Benefits of Modular ComponentsThe modular approach used by FHIR provides a number of benefits:Simplifies understanding\u00a0– Individual resources are smaller in scope and easier to understand than the large, monolithic messages used by HL7 v2.Promotes reuse – Resources have standard APIs, semantics, and bindings. This enables reuse across healthcare workflows and applications.Enables interoperability\u00a0– Modular components with defined semantics are ideal for shareable data.Flexible assembly\u00a0– Resources can be combined in different configurations to exchange data for various clinical use cases.Accelerates development\u00a0– Common resource patterns reduce the learning curve for developers and decrease development time.Lightweight integration\u00a0– Resources can be retrieved on demand versus using static messages with fixed payload. Reduces complexity.Scalability\u00a0– Resources allow for more decentralized and cloud-based access models versus point-to-point message exchange.Overall the resource-oriented paradigm used by FHIR, enables simpler yet more flexible and scalable interoperability compared to past approaches.RESTful APIsThe FHIR standard is based on RESTful web APIs. This differs greatly from HL7 v2.x’s use of tightly-coupled, point-to-point messaging interfaces.REST (Representational State Transfer) is an architectural style for web services. RESTful systems aim to expose data on the web as addressable resources that can be identified using URLs.REST uses standard HTTP methods to perform operations on resources like GET, POST, PUT, DELETE. For example, HTTP GET retrieves a resource, POST creates a new resource, PUT updates a resource, and DELETE removes it.In FHIR, resources are accessed by sending HTTP requests to defined FHIR servers:GET {serverURL}\/Patient\/{id} – Retrieve a patient by IDPOST {serverURL}\/Observation – Create new observation resourcePUT {serverURL}\/Procedure\/{id} – Update existing procedure resourceThis RESTful API model has numerous benefits:Simplicity\u00a0– Uses widely adopted web technologies and protocolsDeveloper experience\u00a0– Leverages existing tooling, libraries, skillsScalability\u00a0– Enables decentralized, internet-scale architectureFlexibility\u00a0– Resources accessed on demand, not predefined messagesSecurity\u00a0– Built-in authentication, authorization, encryptionEcosystem\u00a0– Broad ecosystem of infrastructure, cloud platforms, and vendorsThe RESTful APIs make it much easier to exchange healthcare data between disparate systems. They promote simpler point-to-point data access rather than complex, tightly-coupled interfaces.Comparing Message Exchange PatternsHL7 v2.x uses a message exchange pattern that is transactional, point-to-point, synchronous, and server-driven. Systems send request messages and receive response messages over direct interfaces.This messaging pattern has some limitations:Tight coupling\u00a0– Dedicated interfaces between each systemFixed messaging\u00a0– Rigid message structuresBatch transactions\u00a0– Data exchange done in batchesCentralized\u00a0– Single server controls transactionsIn contrast, FHIR follows a web-based exchange pattern that is resource-focused, ad hoc, asynchronous, and client-driven:Decentralized\u00a0– APIs provide access to data anywhereOn-demand\u00a0– Data accessed when neededStateless\u00a0– No transaction tracking neededMobile\u00a0– Works across multiple device typesCached\u00a0– Enables data to be cached locallyThe RESTful exchange pattern used by FHIR provides greater scalability and flexibility compared to previous approaches. It aligns better with internet-scale access to healthcare information.SecurityBoth HL7 and FHIR require comprehensive security to protect sensitive patient health information being exchanged.HL7 v2.x security relied mainly on point-to-point security controls like VPNs and firewalls.FHIR incorporates modern internet-based security:Transport encryption\u00a0via HTTPSOAuth 2.0 authentication\u00a0using access tokensAccess control using user roles and permissionsAudit logging to track data accessAnonymization to hide personal identifiersDigital signatures on resourcesTLS and HTTPS for end-to-end securityFHIR’s web-based security model aligns with modern application security techniques and can leverage a wide range of tools and libraries.Clinical TerminologiesBoth standards need codified clinical terminologies to represent concepts like diagnoses, procedures, medications, lab results, etc.HL7 v2.x uses keyed codes with some standard code systems like LOINC, SNOMED CT, and RxNorm but allows many custom codes.FHIR emphasizes the use of standard clinical terminologies and ontologies through its “CodeSystem” resource and bindings to global standards:SNOMED CT, LOINC, RxNorm, ICD-10 for clinical codesUCUM for units of measureHL7 v3 data typesPROV for provenance metadataThe use of common global terminologies improves semantic interoperability between systems using FHIR.Converting Between HL7 v2 and FHIRMany healthcare organizations have legacy systems using HL7 v2, yet want to adopt FHIR for new applications and interfaces. This requires converting data between the two standards.The structured nature of HL7 v2 and FHIR make automated conversion possible, but it requires mapping between the models:Segments and delimiters vs. resource data elementsV2 fields and datatypes to FHIR elementsEmbedding v2 messages in FHIR bundlesMapping v2 codes to FHIR terminologiesConverting v2 Send\/Receive interfaces to FHIR APIsLossless roundtrip conversion between v2 and FHIR may not always be feasible due to differences in expressivity. Some implementation-specific details may not fully map.Tooling is emerging to assist with HL7 v2 and FHIR conversion including middleware, integration engines, and mapping tools. But quality transformers still require human understanding of the data models.Clinical Data Analytics Using FHIRThe web-based nature of FHIR makes it feasible to leverage cloud platforms, big data technologies, and clinical data analytics using FHIR data:Cloud deployment of FHIR servers and data storageBig data pipelines to ingest, transform and consolidate FHIR resource dataAnalytics using BI tools, data science, and machine learning on FHIR dataVisualization and dashboards powered by FHIR data APIsClinical decision support based on analysis of patient data trendsPopulation health management analyzing patient cohortsPrecision medicine correlating genomic data with clinical dataClinical trials gathering patient-reported outcomesPublic health monitoring based on analysis of healthcare trendsThe transition to FHIR enables entirely new uses of healthcare data that were impractical with previous standards and legacy interfaces.FHIR Development Tools and LibrariesOne driver of FHIR adoption is the availability of open-source libraries, tools, and plugins that accelerate development:Sample server and API implementationsCode generation tools to speed creation of modelsInterface engines to quick start integrationTesting tools and sample data for implementationsMapping tools to\/from other standardsTerminology services for code lookup and translationMobile libraries on iOS, Android, React NativeSDKs for various languages – Java, .NET, Python, JavaScript, GoORM libraries to persist FHIR models in databasesSupport for FHIR in leading healthcare interoperability platformsFHIR extensions for healthcare-related web protocols like OAuth 2.0Plug-ins for EHR systems and healthcare middlewareThe tooling and support for FHIR will continue maturing to reduce barriers to adoption. But HL7 v2 still has richer legacy tooling support currently.Limitations of FHIRWhile FHIR is gaining momentum, it is not without limitations:Newer standard with less production experience than HL7 v2.xKey specifications like terminology services still evolvingLimited support for financial, administrative, and supply chain workflowsConcerns over bandwidth and caching needed for extensive resource queryingImmaturity of tools for aggregating resource data into clinical artifactsStandards governance and versioning processes still developingGaps in representing complex clinical concepts like genomicsNeed for “gold-standard” reference implementationsChange management from legacy interfaces to FHIR-based infrastructureDespite its limitations, FHIR adoption is accelerating because its overall approach addresses fundamental needs for simpler, web-based healthcare data exchange.Future Outlook for FHIR AdoptionFHIR adoption is expected to rapidly grow over the next 5-10 years across healthcare organizations, EHR systems, consumer apps, medical devices, analytics platforms, and other health IT:U.S. CMS and ONC have mandated access to patient data via FHIR APIsLeading EHR vendors committed to exposing data via FHIR APIsHealth systems rolling out enterprise FHIR capabilitiesMajor growth in FHIR-enabled healthcare apps and digital health toolsEmerging support in medical devices like imaging systems, wearables, and IoMTIncreased use of FHIR for public health data exchange and analyticsGrowth of FHIR in clinical research and patient-centered outcomesHL7 standards under international review to incorporate latest FHIR featuresExpanded FHIR capabilities in integration engines and health data platformsPotential consolidation and deprecation of overlapping standardsDespite its current limitations, FHIR solves real healthcare interoperability needs and has too much momentum to stop. Patient and provider demand for seamless healthcare data access will only accelerate FHIR adoption. It will eventually subsume and consolidate overlapping standards. FHIR aims to finally deliver on the promise of standards-based healthcare interoperability.Summary: HL7 vs. FHIR Commonalities, DifferencesHL7 and FHIR both facilitate healthcare interoperability, but take fundamentally different technical approaches. While earlier HL7 standards paved the way, FHIR represents a major evolution in how healthcare data is modeled, accessed, and exchanged.FHIR provides a simpler, modular, web-based model for exchanging patient health data that better aligns with modern software best practices. Adoption is accelerating to replace dated interfaces. FHIR capabilities will eventually become a baseline requirement for health IT systems.Despite its current limitations as a relatively new standard, FHIR represents the future of healthcare interoperability.Alex J. LauCOO & Co-Founder of Medwave. Over 30 years of experience, in areas of digital marketing, product creation, and operations."},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"2024","item":"https:\/\/medwave.io\/2024\/#breadcrumbitem"},{"@type":"ListItem","position":2,"name":"02","item":"https:\/\/medwave.io\/2024\/\/02\/#breadcrumbitem"},{"@type":"ListItem","position":3,"name":"HL7 vs FHIR: The Key Differences","item":"https:\/\/medwave.io\/2024\/02\/hl7-vs-fhir-the-key-differences\/#breadcrumbitem"}]}]