HL7 vs FHIR: A Comprehensive Comparison | 2025

Posted in HL7

Effective data exchange is paramount in modern healthcare, enabling seamless communication between diverse systems and improving patient outcomes. HL7 and FHIR are key standards that facilitate the secure exchange of PHIs. While HL7 is a well-established standard for healthcare data exchange, FHIR is a newer, more flexible approach designed to address the evolving needs of modern healthcare systems. By understanding the strengths and limitations of both, healthcare organizations can make informed decisions to optimize their data exchange strategies and drive improvements in patient care. Let’s get into comprehensive differences between Hl7 vs FHIR. 

What is the HL7 Interface Engine, and How Does it Work?

HL7, a standardized language for healthcare data exchange, significantly enhances interoperability between various healthcare systems. By providing a standard format for medical information, HL7 streamlines workflows, reduces errors, and improves patient care. It enables seamless communication between different healthcare providers, facilitating faster access to patient information. 

The HL7 interface engine can be seen as an application that translates data from one healthcare system format to another. HL7 is an inter-system bridge that facilitates information exchange between the associated systems. The main objective of the HL7 open source interface engine is to ensure essential patient data is protected and transmitted safely and according to the proper regulations. 

How the HL7 Interface Engine Works

The HL7 interface can be broken down into five HL7 interface tools:

• Data origination: This is where a healthcare system generates health data (lab results, patient demographics, medication orders).
• Data formatting: The HL7 interface converts the health data into the standardized HL7 format.
• Data transmission: The HL7 message is sent to the receiving system.
• Data reception: This is where the receiving system receives the HL7 message and uses the HL7 interface to convert it into a readable format. 
• Data integration: Where the converted data gets integrated within the receiving system’s workflow or database. 

Benefits of Using HL7 

HL7 integration simplifies and streamlines essential processes, ensuring the system does exactly what it needs to do. 

The five areas that HL7 integration improves include:

1. Reduced Errors and Improved Data Accuracy: HL7 integration uses consistent data formats, eliminating transcription errors by automation. Data validation also allows the systems to automatically flag data inconsistencies to ensure the data sent is in the correct order and format, improving data accuracy.

2. Enhanced Patient Care Coordination: Doctors can access updated patient information whenever required. This seamless communication between departments fast-tracks the processes and improves patient outcomes. 

3. Increased Administrative Efficiency: Routine task automation allows hospital staff to focus on patient treatment instead of paperwork. Automating repetitive tasks improves operational efficiency, e.g., faster claims processing and reimbursements.

4. Improved Cost Savings: HL7 data protocols reduce redundancy by eliminating duplicate data and its storage, saving space, and reducing the risk of incorrect results. A streamlined workflow can also increase productivity by helping to complete more work in less time. 

5. Enhanced Patient Satisfaction: Patients more involved and informed about their care are more likely to adhere to treatment and medication regimens. The patient feels comfortable following the doctor’s instructions, ensuring better health outcomes.

What Is FHIR?

FHIR, or Fast Healthcare Interoperability Resources, is a standard set of rules for exchanging electronic healthcare data. It is flexible and easily adaptable, making it useful in a wide range of settings and with different healthcare information systems. FHIR aims to enable the seamless and secure exchange of patient data so that patients can receive the best possible care. 

Benefits of FHIR’s Data Model

Unlike conventional data models, FHIR offers greater flexibility due to its resource-based architecture, RESTful API, extensibility, and support for diverse data types. This allows for customization, seamless integration, and representation of a wide range of healthcare information.

Global Community and Support

FHIR has a comprehensive network of servers worldwide, supporting user interactions that include HR managers, governments, organizations, universities, and hospitals to create a supportive global community. 

Online Collaboration Platform

The platform chat.FHIR.org provides a free, 24/7 online space for implementing individuals to ask questions, share insights, propose ideas, and engage in meaningful discussions.

Easy Implementation 

FHIR emphasizes quick implementation, focusing primarily on implementers and developers, ensuring that the standard meets the needs of the majority.

Usability Focus

FHIR follows the 80:20 rule. It ensures that the standard’s features are usable and needed by at least 80% of users globally. The remaining 20% allows for easy-to-use extensions. 

Open Access and Licensing

FHIR’s specifications are licensed under Creative Commons CC0, one of the least restrictive licenses. This enables users to access all features without cost.

Fast Adoption

FHIR is designed for fast adoption. It includes approximately 150 resource-specific data models for various healthcare purposes.

Examples of Resources

Some essential resources include:

• Patients: Critical for healthcare applications.
• Encounters: Documenting hospital visits.
• Observations: Capturing clinical findings.
• Diagnostic Reports: Summarizing test results.
• Medications: Managing prescriptions.

Data Types in FHIR

Like programming languages, FHIR employs fixed data types such as: 

• Strings
• Booleans
• Dates
• Decimals

FHIR Vs HL7

What is the difference between HL7 and FHIR? FHIR uses RESTful web services and open web technologies like XML and JSON, while HL7 only supports XML.

FHIR standard was released as an alternative to HL7 v2 to improve interoperability and communication by enabling new apps and legacy systems to exchange data easily. It leverages modern web technologies like RESTful APIs and JSON. JSON, a lightweight data-interchange format, is more concise and efficient than XML, making it a popular choice for data exchange over the internet.

HL7 is a clinical messaging format that supports the secure exchange of healthcare data between medical organizations. It uses ASCII text-based messages to communicate between different systems, such as patient management systems, healthcare information systems, EMRs, laboratory information systems, and billing systems. To structure and store this data, HL7 XML (Extensible Markup Language), a markup language that uses tags to enclose data elements, making it hierarchical and easy to read for both humans and machines.

HL7 VS FHIR Standards

HL7 provides a framework for exchanging, integrating, sharing, and retrieving electronic health information. HL7 standards define a process for packaging and communicating information from one party to another, as well as the language to be used and the correct structure and data types required for seamless integration between systems.

HL7

HL7 standards support managing, delivering, and evaluating clinical practice and health services. Some common primary HL7 standards include Clinical Document Architecture (CDA®) Products, context management specifications, HL7 Version 2 Product Suite, and HL7 Version 3 Product Suite, while messaging and document standards for clinical specialties and groups include Arden Syntax, HL7/ANSI standards, HL7 Consumer Mobile Health Application Functional Framework, HL7 EHR-S Functional Requirements, and hundreds of others.

FHIR

FHIR® is also an interoperability standard of HL7 intended to facilitate the exchange of healthcare information between healthcare providers, patients, caregivers, payers, researchers, and anyone else involved in the healthcare ecosystem. You can also call it the latest version of HL7.

FHIR contains two sections: a content model in the form of ‘resources’ and a specification for exchanging these resources via RESTful interfaces, messaging, and Documents.

FHIR is known to help researchers exchange information, and its two sectors collectively ensure better resource management. However, how the FHIR system is developed can impact the information exchange between researchers.

For this reason, you must choose a vendor that conducts in-depth UX research in healthcare to ensure the information exchange is secure, optimized, and error-free.

Some common FHIR standards include HL7 Fast Healthcare Interoperability Resources Specification, HL7 FHIR® IG: Payer Coverage Decision Exchange, HL7 FHIR® Implementation Guides on Bulk Data, bidirectional services, C-CDA on FHIR, clinical decision support for immunization, coverage requirements discovery, consumer-facing real-time pharmacy benefit check, electronic case reporting, healthcare-associated infection reports, payer coverage decision exchange, consumer-directed payer data exchange, structured and unstructured data capture, unsolicited notifications, and data exchange for quality measures.

HL7 VS FHIR Protocols

HL7

HL7 is a message-based approach that defines specific message types (e.g., ADT, ORU, ORM) with fixed structures and data elements.

HL7 Protocols: Although HL7 does not have specific protocols, it depends on underlying protocols to transmit messages, including:

• HTTP: For web-based communication
• FTP: For file transfer
• SMTP: For email-based transmission

HL7 messages are often transmitted in a specific format, such as HL7v2, which can be complex to implement and integrate.

FHIR

On the other hand, FHIR is a modern standard with a resource-based approach. It defines a set of resources (e.g., Patient, Observation, Medication) that represent various healthcare concepts. FHIR uses RESTful APIs for communication, making integration easier.

FHIR Protocols: FHIR primarily relies on HTTP-based protocols to interact with resources. These include:

• GET: To retrieve a specific resource
• POST: To create a new resource
• PUT: To update an existing resource
• DELETE: To delete a resource

HL7 V2 VS FHIR

Even though FHIR supports messaging (similar to HL7 V2), it also supports multiple options for facilitating data exchange among systems. However, between HL7 v2 vs FHIR, FHIR is more advantageous because it provides more flexibility. The main difference between HL7 vs FHIR lies in the fact that, unlike HL7 v2, FHIR employs RESTful web services and open web technologies, such as JSON and RDF data formats. 

Since most developers are acquainted with these technologies, they experience a less steep learning curve than previous standards. The RESTful API approach replaces point-to-point interfaces with one-to-many interfaces, making it much easier to exchange data and minimize the time to onboard new data exchange partners. 

Another major benefit of the RESTful approach is that it increases interoperability between not just electronic health record (EHR) systems but myriad other devices and systems, such as mobile apps and wearables. 

Another difference between HL7 v2 and FHIR is that the former still depends on document exchange for health information exchange and data interoperability. Providers using HL7 v2 typically choose a set of data to transmit and then generate a message enveloping that data. HL7 v2 still uses the Consolidated Clinical Document format that contains a great deal of critical information; just like the static data in a PDF, extracting the information and making it usable in any other format becomes quite laborious. 

This type of document exchange limits the provider from digging deep into the context of the data received. Further, in our debate of FHIR vs. Hl7 v2, data-level change is critical in many applications, so FHIR leverages standardized application programming interface (API) standards to transcend data reconciliation challenges. Using FHIR, applications can be plugged into a basic EHR operating system, and information can then be fed into the provider’s workflow automatically.

Like segments in HL7 v2 messages, FHIR stores and exchanges meaningful pieces of data known as “resources.” Each resource contains metadata, text, or bundled collections of information that form clinical documents. The best thing about the resource concept is that each has a unique identifying tag, which helps devices and applications access required data without complicated data exchange processes.

Why Is FHIR Better Than HL7?

The idea behind the development of FHIR is to create a basic set of resources that, individually or in combination, can solve real-world clinical and administrative problems at a fraction of the price of existing FHIR alternatives. Like segments in an HL7 v2, each FHIR resource can be sliced into types and groups, wherein each type has a unique field structure with either composite or primitive values. These fields are optional or compulsory; the resources are based on XML, Atom, JSON, HTTP, and OAuth. Although a single resource may suffice for a given use case, resources are often combined and tailored to meet use case-specific requirements.

Another reason why FHIR is better than HL7 is that it offers numerous options for exchanging data among systems. In addition to supporting the messaging format of HL7, the FHIR system leverages the RESTful API approach. This allows FHIR to improve interoperability among various systems and devices beyond electronic health record (EHR) systems.

FHIR also promises to improve information sharing, simplify implementation, and offer better support for mobile apps. One area where FHIR especially stands out is its ability to support vital use cases that benefit providers, payers, and patients. FHIR will also facilitate patient data sharing between clinicians to provide coordinated care to patients and enhance critical decision-making. Insurance companies can use FHIR to supplement claims data with clinical data to verify details and improve outcomes. This would also solve a lot of false insurance claims and cut down on costs. As for patients, FHIR will allow patient-led care and allow users to become more involved in their healthcare and access medical information through consumer-friendly apps on the devices of their choice.

Current interoperability efforts, such as HL7, only operate with a single aim: moving data back and forth and removing data reconciliation obstacles. On the other hand, FHIR aims to coordinate care plans across system boundaries with the help of mobile devices and easily accessible apps. By incorporating apps that can be plugged into the basic EHR operating system and feed information directly into the provider workflow, FHIR aims to remove many issues associated with document exchange.

What is the HL7 To FHIR Converter?

The FHIR Converter can convert legacy data (currently HL7 v2 messages) into FHIR bundles. Converting legacy data to FHIR expands the use cases for health data and enables interoperability. Folio3 medical app development services make it easy to convert HL7 v2 messages into FHIR bundles.

HL7 V3 Vs FHIR

Here are some basic differences between FHIR and HL7 v3 to help you differentiate between them.

While FHIR has modern integrations and flexibility to offer, HL7 V3 provides a structured framework for data exchange. HL7 v3 establishes rigorous types and an electronic healthcare paradigm based on XML-based communications. The RIM (Reference Information representation) idea, which denotes a static representation of medical data, is introduced in the HL7 V3 standard. It offers data kinds, messages, and terminologies. 

The open-source model is utilized by the standard that is implementers-focused, FHIR. It is accessible for study and application, unlike earlier healthcare norms. The community’s interest has substantially increased, and developers are involved in standard development and testing thanks to the standard’s accessibility. It should be highlighted that smooth data interchange and integration within the sector are being made possible in both hl7 v3 and fhir, redefining healthcare interoperability.

How To Convert HL7 To XML?

It is quite easy to convert HL7 to XML. While performing this adjustment, it is helpful to remember that two objects are generated when a message is received. The first is the “Source,” and the second is the “Message.” Both items initially resemble one another perfectly and include a replica of the message sent. 

There are two methods for finishing this project. For straightforward XML files, it could be simpler to map each field in the HL7 message independently.

The first step is converting the message object from an HL7 message type to XML.

message = qie.createXMLMessage(“”, ‘UTF-8’);

Next, map the source HL7 Nodes to the XML XPATH in step two. 

The patient ID is copied to the XML patient identifier node path in the following sample line of code.

message.setNode(“/Patient/identifier/@value”, source.getNode(“PID-3”));

In the final step, you must assess the template and produce the XML message. The template is first obtained and then passed to the qie.evaluateTemplate method. The data from a particular message replaces the HL7 Node Tags in this method. The new XML message is then used to generate the message object. 

Folio3 Digital Health: Your trusted partner for expert HL7 and FIHR Integration Solutions

HL7 and FHIR integration is essential for secure, seamless healthcare data transmission. Various components are involved, and the Folio3 Digital Health knows how to make it come together. Our team of expert designers, developers, marketers, and testers can help with everything from ideation to final deployment and post-deployment support. 

Every Folio3 Digital Health product is HIPAA-compliant and uses the latest HL7 and FHIR interoperability standards. Our digital health products offer immense value, adhere to essential regulations, and come with support from start to finish. 

Conclusion

Both HL7 and FHIR are crucial standards for healthcare data exchange. HL7 is a traditional rule structure that offers a framework for data exchange, while FHIR, a modern standard, provides a more flexible and interoperable solution.

By adopting these standards, healthcare organizations improve patient care, reduce operational costs, and contribute towards better decision-making. However, successful implementation requires careful planning, robust security measures, and ongoing maintenance. As healthcare continues to evolve, these standards will play a critical role in shaping the future of healthcare delivery.

Frequently Asked Questions

HL7 FHIR vs CDA, Which One is Better?

Clinical Document Architecture is limited to “clinical” use cases or data that deal with patients and their health conditions. This model doesn’t facilitate the exchange of content that isn’t clinically relevant, such as financial information. On the other hand, HL7 FHIR documents have no limitation on their content and can include data about different aspects of healthcare, such as billing and insurance.

Similarly, in CDA, the “content” of the document is expressed using a complex model, which gives implementers the flexibility to express a clinical concept in any degree of granularity. This model poses many challenges, for instance, when representing a person’s allergies or surgery. Templates are required to support interoperability. No such problems exist with FHIR since all clinical (and non-clinical) content in a message is handled by referencing existing resource definitions. 

Are FHIR vs HL7 Message Types Different?

HL7 uses a fixed format with specific message types (e.g., ADT, ORU, ORM) and data elements. It typically relies on XML for data exchange. Meanwhile, FHIR uses a more flexible, resource-based approach with various communication data formats (XML, JSON) and RESTful APIs.

How To Configure Authorization/Access Control in a FHIR Store?

A FHIR system needs a security sub-system that administers users, user authentication, and user authorization. In Role-Based Access Control (RBAC), users need permissions for every object they wish to access. Permissions are grouped into roles, wherein each role characterizes the functions a user can perform. If a user’s role is granted permission to access an object, they can readily access it. FHIR supports this form of access control since FHIR Resources are object types, and events such as Create, Read, Update, Delete, and Execute are operations on those objects. 

How Much Does HL7 Integration Typically Cost?

The cost of HL7 integration depends on patient data volume, HL7 system complexity, and custom additions. These are some average values: 

• Small-scale integration, i.e., two systems with limited data exchange: $10,000 – $50,000
• Medium-scale integration, i.e., integrating multiple systems with moderate data volume: $50,000 – $200,000
• Large-scale integration, i.e., enterprise-wide integration with high data volume: $200,000+

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