In the healthcare industry, the adoption of standards for the transfer of clinical and administrative data between software applications is crucial. Health Level Seven or HL7 is a set of international standards that has been widely adopted in in-patient settings throughout the world. HL7 v2 is its first information exchange standard and is still widely used, but the introduction of Fast Health Interoperability Resource (FHIR) has brought about a new trend in healthcare data-sharing platforms. In this blog, we will explore the pros and cons of HL7 v2 and FHIR, and how Health-Tech companies can utilize the best of both worlds based on their use case.
Wide adoption: HL7 v2 is widely adopted and used in various healthcare settings worldwide. Many systems have been developed that use HL7 v2, and it has a well-established community.
Granularity: HL7 v2’s “Segment” structure provides re-usable chunks of data that roughly correspond to FHIR’s idea of resources. However, HL7 v2 segments can’t be independently manipulated. Additionally, not all segments have the characteristics of independent identity held by FHIR resources. Due to differences in scope and approach to extensibility, HL7 v2 segments and data types are frequently cluttered with data elements that are not used by (or even understood by) the majority of implementations.
Segmentation: HL7 v2’s “Segment” structure provides re-usable chunks of data that correspond to FHIR’s idea of resources. HL7 v2 segments can be composed into repeating and/or optional collections called “groups” to represent full healthcare business objects.
Inter-version compatibility: HL7 v2 has strict processes for maintaining forward and backward compatibility, ensuring that systems can communicate with each other even if they are running different versions of the standard.
Extensibility: HL7 v2 provides an extensibility mechanism through the use of “Z-segments“, but the meaning of these extensions is opaque without prior manual explanation by the sender.
Human Readability: HL7 v2 instances do not provide for human-readable versions of the content exchanged, which can make it difficult for non-technical users to understand.
Update behavior: HL7 v2 data is typically exchanged in “snapshot” mode, which can be inefficient and cause data redundancy.
Event-based: FHIR supports an event-based messaging paradigm similar to the HL7 v2 messaging structure, which is widely adopted in the healthcare industry.
Extensibility: FHIR Extensions can appear at any level, and the meaning of FHIR extensions is discoverable by resolving the URI that defines the extension.
Human Readability: FHIR requires human-readable content to be provided for each resource, making it easier for non-technical users to understand.
Limited adoption: FHIR is a relatively new standard, and its adoption is not as widespread as HL7 v2.
Update behavior: Out-of-the-box, FHIR only functions using snapshot mode, which can be inefficient and cause data redundancy.
Optionality & Profiles: FHIR resources are much more limited in terms of what elements are included in the core specification compared to HL7 v2.
Health-Tech companies should understand the pros and cons of HL7 v2 and FHIR to utilize the best of both worlds as per the use-case. HL7 v2 is a well-established standard and is widely adopted, while FHIR is a new standard that offers event-based messaging and better extensibility. HL7 v2 is a good option for systems that require strict inter-version compatibility, while FHIR is a good option for systems that require better extensibility and human readability. It is essential to choose the standard that best fits the specific needs of the system and to explore the potential benefits of using both standards together.