A Comprehensive Comparison Between HL7 vs. FHIR

One of the key challenges faced by large healthcare organizations is interoperability. Major U.S. cities have high rates of interoperability of health data, but variation exists. An organization that runs on multiple systems such as practice management, EHRs, or patient portals is bound to face data exchange problems. Small-sized clinics face fewer interoperability issues compared to larger organizations. So, to tackle this issue, certain data exchange standards were introduced, such as HL7 (Health Level Seven International) and FHIR (Fast Healthcare Interoperability Resources).

Both these standards are exceptional at ensuring interoperability, but there are certain aspects that sets them apart. In this article we will be taking a deep dive into HL7 vs. FHIR, so you can select the standard that works best for you.

HL7: A Brief Overview

HL7 is a standard used in the healthcare industry to exchange data between different systems. It is designed to be flexible and interoperable, thereby ensuring seamless data exchange. HL7 promotes data sharing of records, lab reports, test results, etc., through clinical applications. HL7 message structure includes segments, fields, components, and sub-components. This standard has different versions – HL7 V2, V3, CDA, and FHIR. Let’s understand about them.

1. HL7 V2

The HL7 V2 or version 2 standard was developed to offer a framework in which information is exchanged between disparate clinical systems.

It may not be as widely used as FHIR, but it ensures organization-wide interoperability between healthcare systems. This version of HL7 uses standardized messages such as medical orders, demographics, lab results, administrative activities, and financial details.

One interesting fact about HL7 V2 is that it can offer 80 percent of the interface while the rest 20 percent needs customization. This helps in achieving flexibility in optional and repeating segments.

2. HL7 V3

So, HL7 V3 or version 3 was developed to address certain challenges faced in the HL7 V2 standard. These challenges are as follows:

1. A lack of a consistent data model, it is more implied.
2. It lacks well-defined roles for messages and applications used in varied clinical operations.
3. HL7 V2 offers a lot of flexibility, leaving little room for a full solution.

The goals of HL7 V3 are:

1. To increase worldwide adoption of the V3 standard.
2. To have a consistent data model.
3. To develop a more accurate and not a vague standard.
4. Create a completely new standard that is not hindered by legacy problems.

3. CDA

The HL7 CDA (Clinical Document Architecture) is an XML-based standard that offers a structure or format for sharing clinical data such as progress notes, discharge summaries, and consultation notes.

CDA includes the following elements for all clinical documents – stewardship, persistence, potential for authentication, wholeness, context, and human readability.

A Synopsis of FHIR

According to a document on the HL7 page, “The philosophy behind FHIR is to build a base set of resources that, either by themselves or when combined, satisfy the majority of common use cases. FHIR resources aim to define the information contents and structure for the core information set that is shared by most implementations.”

A FHIR resource is divided into four parts:

1. Metadata: It includes the resource details such as resource version ID and date of the resource creation.
2. Extensions: Extension is a figment of a resource used to add data that initially is not part of a specific resource structure.
3. Narrative: Here, the resource content is presented in HTML format.
4. Standard Data: The block encompasses the patient’s name, medical record number, gender, information about the care provider, birth date, etc.

To extract the full benefits of FHIR, use SMART on FHIR which is an open-source API that allows developers to build applications that can operate anywhere in a healthcare system.

One of the uses of FHIR: In 2021, the University of Pittsburgh Medical Center inducted FHIR to increase interoperability across the organization, with an aim to connect hospital-based EHR with ambulatory EHR systems.

HL7 vs. FHIR

1. Tackling Security Concerns

Hackers can exploit the MLLP (Minimum Lower Layer Protocol). This is a framing mechanism to standardize HL7 messages for transmission over IP/TCP networks. Here, the IP Address, basic HL7 message format knowledge, and TCP port are enough for a hacker to send unauthorized messages and cause significant damage.

Another type of security damage can be a man-in-the-middle attack. This takes place when a hacker obstructs HL7 messages. This is done by obtaining access to the communication channel.

Plausible solutions could be to install a VPN or to get expert help from a healthcare software development company.

FHIR offers improved security features compared to HL7. This standard supports OAuth2 and OpenID Connect which safeguards sensitive data from unauthorized access. HL7 FHIR also relies on RESTful APIs and open web standards, which offer a safe foundation for integration and data exchange.

2. Ways of Data Exchange

RESTful APIs of FHIR replace point-to-point interfaces with one-to-many interfaces. This simplifies the process of onboarding new data exchange partners. It also speeds up the data-sharing process.

HL7 Messages are used to transfer healthcare data between disparate systems, each sending information about events such as patient admission. These messages are in human-readable format, but they may need some time to interpret. Basically, HL7 banks on traditional messaging systems for data exchange compared to modern FHIR.

3. Interoperability

FHIR encourages real-time data integration, exchange of healthcare information, and improved alignment with clinical decision-making, all of which ensure interoperability. This eventually leads to better patient outcomes, as providers can access and use the data to make informed care decisions.

Furthermore, FHIR supports integration with legacy systems, providing an adaptable and flexible solution for providers who are looking to transit toward modern data exchange standards.

HL7’s interoperability abilities are limited compared to FHIR due to its reliance on XML formats and traditional messaging systems.

4. Architecture and Design

Fast healthcare interoperability resources runs on RESTful API architecture, which facilitates data sharing over HTTP by using FHIR CRUD (Create/Read/Update/Delete) operations. It also manages large volumes of data from various sources. Furthermore, FHIR helps varied healthcare platforms to share data effortlessly. Plus, FHIR’s resources store healthcare data in structured format, making it manageable and accessible.

On the other hand, HL7 standard functions on segment-based structure, where information is transmitted in a predefined structure, assuring that every bit of data resides in a pre-decided segment. The HL7 standard can become complex and rigid due to its necessity for accurate parsing and interpretation.

5. Messaging Templates

FHIR standard supports XML and JSON messaging formats, thus providing flexibility for healthcare systems. Out of the two formats, JSON is easily readable and lightweight, thereby making it an ideal choice for apps and mobile devices.

However, HL7 standard primarily uses XML format, which is challenging to parse and read, especially on smartphones. XML was used in healthcare systems, but JSON is a much versatile option that can cater to the growing demands of better data exchange and mHealth apps.

6. Performance Analysis

The HL7 standard has a segment-based message structure and is quite effective for legacy systems, but can result in slow data transmission. Conversely, FHIR’s resources optimizes data exchange via JSON and XML formats. FHIR also speeds up data retrieval and decreases data redundancy.

HL7 vs. FHIR: Which is Better?

There’s no right or wrong decision here. FHIR and HL7 V2, V3, and CDA are specialized in different aspects. If you’re looking for better interoperability, then go for FHIR because its JSON format ensures better readability and data exchange. So, the choice on what to choose depends on organization’s requirements.

If you’re still in a dilemma, then bring in an expert to help you out in finding a solution. Approaching a renowned healthcare software development company can be beneficial in choosing the right standard for your organization. Arkenea has been delivering top-notch healthcare software solutions from the last 14 years. And we can help you solve your issues effectively. To know more just get in touch with us.