Is there a SNOMED API?
Collection: Technology adoption
Summary: Yes, multiple SNOMED APIs are available to provide access to terminology services for health information systems. These local or hosted APIs enable developers to integrate SNOMED CT into their applications, ensuring consistent and standardized use of medical terminology.
Technology use case
An API (Application Programming Interface) is a set of rules and protocols that allows different software applications to communicate with each other. In the context of a terminology service, an API acts as the interface through which developers can access and use the features of the terminology service, such as searching for medical terms, retrieving definitions, or managing subsets of terminology data. This interface allows external systems to interact seamlessly with the terminology service without needing to understand its internal workings, thereby enabling integration and interoperability.
Using terminology services1 is essential for health information systems because it enables standardized communication between different systems and applications. Modern terminologies are updated frequently, utilize complex data representations, and require advanced indexing mechanisms to support real-time responses.
Utilizing terminology services represents a good separation of concerns, allowing the terminology server to handle terminology management while enabling other components of an application to focus on their core responsibilities, such as recording and displaying clinical data and supporting clinical workflows. This makes systems more modular, flexible, and maintainable.
SNOMED-Specific Terminology Servers
SNOMED-specific terminology servers2,3 provide advanced functionalities for browsing, searching, and retrieving SNOMED CT concepts, ensuring compatibility with SNOMED query languages like ECL (Expression Constraint Language). These servers help systems take full advantage of the advanced features of SNOMED CT and provide tools for managing SNOMED extensions, subsets, and mappings.
Terminology servers with SNOMED-specific support may also be compatible with the SNOMED Syndication standard, allowing for automatically updating the terminology by subscribing to a content feed.
FHIR Terminology APIs
The FHIR Terminology Module4 provides a standardized way to access any terminology or classification, and includes all the necessary parameters to support SNOMED content. Systems integrating with a terminology server using a FHIR API can easily swap one terminology server for another, avoiding vendor lock-in.
Local vs. Hosted APIs
Local APIs are typically hosted within an organization's infrastructure and provide quick, secure access to terminology services. They are well-suited for use cases where data privacy and low latency are priorities. Hosted APIs, on the other hand, are hosted by external providers and are useful for organizations without the resources to maintain their own terminology servers. Hosted APIs are provided as a service with various security characteristics and service-level agreements.
Advice
Using a terminology server is the recommended best practice as it centralizes terminology management and ensures consistent access across all systems.
Using the FHIR API provides significant flexibility by offering a standardized protocol for interacting with terminologies, making switching or upgrading terminology servers easier without requiring major changes to the existing system. This flexibility helps future-proof your application and allows for seamless integration of additional terminologies when needed.
If you have the resources and technical capability, hosting your own API is ideal, as it gives full control over configuration, security, and performance. However, for organizations without in-house expertise, partnering with a trusted vendor to host the SNOMED API can simplify implementation and maintenance. Vendors often provide additional support, regular updates, and service level guarantees that can be beneficial in clinical environments.
When choosing whether to use an open-source or commercial server solution to deploy a local API, weighing the pros and cons is important. Open-source solutions offer greater customization and cost-effectiveness, while commercial solutions provide dedicated support and stability. Organizations must consider their internal capabilities, the level of customization required, and the importance of vendor support to determine the best approach.
Try a SNOMED API
SNOMED International makes available a public training API: https://snowstorm-training.snomedtools.org/fhir
Example API Request: https://snowstorm-training.snomedtools.org/snowstorm/snomed-ct/fhir/CodeSystem/$lookup?system=http://snomed.info/sct&code=195967001
Retrieves the details of the concept “Asthma”, id: 195967001
This API is intended for testing purposes, providing access to SNOMED CT using the FHIR Terminology Module resources and operations. However, it should not be used in a production environment or for real clinical data entry. The server does not guarantee uptime or latency, may undergo maintenance without prior notice, and is actively monitored to limit usage to simple test requests. Users and IP addresses may be blocked to prevent abuse.
Tips for best results using a SNOMED API
Use a Terminology Server: Utilize a dedicated terminology server to centralize terminology management and ensure consistent access across all systems.
Leverage FHIR API: Use the FHIR API to gain flexibility, making switching or upgrading terminology servers easier without major system changes.
Host Your Own API if Possible: If resources allow, host your own API to gain full control over configuration, security, and performance.
Consider Vendor Solutions: If in-house hosting is not feasible, partner with a trusted vendor that offers support, regular updates, and service level guarantees.
Evaluate Open-Source vs. Commercial Solutions: Determine if an open-source server meets your needs or if you require the dedicated support and stability of a commercial solution.
Try the public training API provided by SNOMED International.
References
Rector, Alan L., et al. "A terminology server for medical language and medical information systems." Methods of information in medicine 34.01/02 (1995): 147-157.
Snowstorm, an Open Source terminology server: https://github.com/IHTSDO/snowstorm
Metke-Jimenez, Alejandro, et al. "Ontoserver: a syndicated terminology server." Journal of Biomedical Semantics 9 (2018): 1-10.
FHIR Terminology Module: https://hl7.org/fhir/r4/terminology-module.html
Learn More
To learn more, please reach out to [email protected].
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