FHIR vs HL7: The Battle for Interoperability in Cloud-Based Healthcare

Data interoperability has always been an important issue in the healthcare ecosystem. Various healthcare providers and medical tech applications depend on data transformation across different systems and platforms. However, it is necessary to maintain seamless communication and exchange of patient information for an individual’s privacy and the organization’s security.

Unfortunately, the healthcare industry suffers from a lack of standardization. Fragmented data creates various challenges ,such as interoperability barriers between Electronic health records (EHRs), incompatible formats of data, and inefficiency in sharing patient data securely.

Volunteers created the HL7 committee in 1987 to address these problems among healthcare applications. The initial members followed by thousands of healthcare providers, vendors, and consultants dedicated their time to creating a strong foundation for the HL7 standards. Today, most of the clinical interfaces are built and deployed using these standards.

Since 1987, the variety of information has increased vastly due to advancements in the medical field. The complexity of healthcare data and the volume of data generated needed real-time access. The revolution of mobile device usage also demanded immediate access to data on request. In 201, HL7 began with a project that could meet these increasing demands. Thus the FHIR standard was created.

FHIR (Fast Healthcare Interoperability Resources) was first considered as an interoperability standard, but as its use has grown and the community has grown, it has incorporated itself into other parts of the healthcare system. FHIR provided standards for building applications and flexibility for adapting them for specific purposes.

In this blog, we will provide detailed information regarding HL7 and FHIR and the differences between them. We aim to enable industry professionals to understand the healthcare interoperability standards better and offer them to understand how these data exchange standards enable comprehensive interoperability. Let us begin –

Understanding HL7 & FHIR

HL7, or Health Level Seven, refers to a globally recognized standard for exchanging clinical and administrative data between healthcare applications. Think of it as a common language that allows various healthcare systems, like EHRs and lab equipment, to communicate seamlessly. HL7 has played a critical role in promoting interoperability in healthcare data exchange.

While HL7 has been a successful standard, it also has limitations, such as complexities in representing certain clinical findings and limited ability to capture the sequence of patient episodes. However, HL7 continues to evolve, with newer versions addressing these limitations and promoting even better healthcare data exchange.

There are three main versions of HL7 –

HL7 Version 2 (v2):

Released in 1987, v2 is the most widely used version. HL7 v2 focuses on hospital workflows through electronic messages for administrative, logistical, financial, and clinical processes. HL7 v2 uses a specific format with segments and data elements separated by pipes, this is why it’s sometimes called “PipeHat”. Different versions exist (v2.1, v2.2, etc.), but they are mostly backward compatible, meaning a newer system can understand messages from an older system. The HL7 v2.3 and v2.3.1 are the most commonly used versions in practice.

HL7 Version 3 (v3):

Introduced later, v3 has a more complex structure based on a formal language called Resource Description Framework (RDF). HL7 v3 aims to be more semantic, meaning the data includes its meaning in addition to the value. While powerful, v3’s complexity has limited its adoption compared to v2.

FHIR, which stands for Fast Healthcare Interoperability Resources, is a modern standard designed to streamline healthcare data exchange. It emerged as a response to the limitations of previous HL7 versions, particularly v2, in addressing the growing need for seamless information sharing within the healthcare ecosystem.

FHIR Versions

While HL7 started the journey for healthcare data sharing, FHIR (Fast Healthcare Interoperability Resources) took it further, fixing the issues found in older HL7 versions and designed to be flexible for a cloud-based healthcare world. Here’s a look at the FHIR versions :

DSTU2 (Development Snapshot for Trial Use Release 2): Released in 2015, DSTU2 served as a foundation for FHIR’s development. It established core concepts like resources, data types, and APIs. While not widely used today, DSTU2 paved the way for more mature versions.

STU3 (Standard for Trial Use Release 3): Released in 2017, STU3 offered significant enhancements over DSTU2, with a wider range of resources and improved functionalities. While still used in some regions, R4 has become the dominant standard due to its increased maturity and feature set.

R4 (Release 4): Published in 2019, R4 represents the current gold standard for FHIR. It boasts a comprehensive set of resources encompassing various aspects of healthcare data, along with robust security features and improved interoperability. As of 2024, R4 enjoys widespread adoption in the healthcare industry.

Here’s what makes FHIR v3 a modern approach –

▪️Web-based technology: Unlike v2’s reliance on specific message formats, FHIR utilizes RESTful APIs and open web technologies. This allows quicker and more efficient data exchange, similar to how travel websites interact with airlines.

▪️Focus on interoperability: FHIR promotes seamless data exchange among healthcare information systems. This breaks down data silos and enables better care coordination between providers, payers, and patients.

▪️Simplified development: FHIR’s API approach makes it easier for developers to build applications that can access and share healthcare data. This reduces development time and effort compared to v2’s complex structure.

▪️Flexibility: FHIR offers a modular structure with resources, which are self-contained information units. This flexibility allows for easier customization and adaptation to specific healthcare data exchange needs.

▪️Patient-centric: FHIR recognizes the importance of patient engagement in healthcare. It supports patient data and empowers patients to share their information more easily.

FHIR represents a significant shift towards a more modern and efficient way to exchange healthcare data. It paves the way for improved care coordination, better patient outcomes, and a more connected healthcare system.

FHIR uses web services and resources for easier data exchange, making it faster and more flexible than previous HL7 versions. It aims to improve interoperability, simplify development, and empower patients in data sharing. Though not a complete replacement, FHIR offers a significant advancement for healthcare data exchange.

Related read: Decoding SMART on FHIR for Healthcare Interoperability