FHIR vs REST: What are the differences?

Introduction:

FHIR (Fast Healthcare Interoperability Resources) and REST (Representational State Transfer) are both protocols used in healthcare systems to exchange data. While both are widely used, there are distinct differences between the two.

1. FHIR Resource Model vs. REST Resources:

One key difference between FHIR and REST is the nature of the resources they use. FHIR follows a resource-oriented model, where different types of resources are defined and can be exchanged between systems. These resources have specific attributes and can be organized in a hierarchical structure. On the other hand, REST uses a more generic approach with resources being any data element that can be addressed with a URL.

2. Standardized Data Formats vs. Media Types:

FHIR emphasizes the use of standardized data formats such as XML or JSON to represent and exchange healthcare data. It provides specific profiles and guidance on how to structure the data and uses well-defined data elements. REST, on the other hand, does not enforce any particular data format and can use different media types depending on the system's implementation.

3. Complexity and Extensibility:

FHIR is designed to be more complex and extensible compared to REST. It provides a wide range of resources and capabilities to handle complex healthcare scenarios. FHIR resources can be extended with additional attributes or even new resource types to accommodate specific requirements. REST, on the other hand, is simpler and more limited in its capabilities, requiring additional layers or protocols for handling advanced functionality.

4. Navigability and Discoverability:

FHIR inherently supports navigability and discoverability of resources through its defined resource structure. Resources can reference other resources, allowing systems to easily navigate through related data elements. REST, while it does provide the capability to navigate between resources, relies heavily on explicit links or documentation to discover related resources or actions.

5. Compliance with Standards vs. Flexibility:

FHIR is built on existing healthcare standards and protocols such as HL7, ensuring compliance with industry regulations and practices. It promotes interoperability and data exchange among different healthcare systems. REST, on the other hand, provides more flexibility and can be implemented in various ways, potentially compromising compatibility and interoperability.

6. Built-in Healthcare Domain Knowledge:

FHIR incorporates healthcare domain-specific knowledge within its resource definitions and data elements, allowing for better representation and understanding of healthcare-related concepts. REST, being a more generic protocol, does not inherently possess this domain-specific knowledge, requiring additional effort to interpret and process healthcare data.

In summary, FHIR uses a resource-oriented model, standardized data formats, and offers more complexity and extensibility compared to REST. It supports navigability and compliance with healthcare standards, while incorporating built-in healthcare domain knowledge. REST, on the other hand, offers a simpler approach, with more flexibility and broader applicability beyond healthcare.