HL7® FHIR® Profiling – it’s what it’s all about!

by: Amos Bordowitz

The power of FHIR profiling

Part of the power of FHIR® stems from its profiling system. If you ever used HL7® V2, you know that the main hindrance form interoperability is the requirement that each side of the data transaction had to have an agreed-upon schema for every message type. That certainly guaranteed interoperability between both sides of each transaction but had no impact on the ability to send and receive with ither organizations.

Enter FHIR® and its profiles. Profiles are the basic set of rules which must be met for a document to be recognizable by any organization using the FHIR standard. A profile is defined in advance by whatever body governs the project – while most documents can be based immediately on the base profiles defined by HL7, some might have to be extended in some ways to meet the specific needs of the country or organization. For example, in Israel we have HMOs, and every citizen must belong to one of them. As this is an Israel-centric issue, there was no point in defining this ability in the original Patient profile.

So, the important steps in profiling are first, to recognize what is required from the profile. Try to think of the basic use-cases and derive from there. Once you have done this, the next step is to look at the base profile on the HL7® FHIR® website and see if the base profile answers all your needs. If the answer is no, then you might think incorrectly that you then must write an entire profile yourself – a daunting prospect in many cases, as the JSON or XML of a profile can run at thousands of lines of code at times. But FHIR comes to the rescue once again!


The true power of FHIR is inheritance. If you know that the base profile encapsulates all but a few small differences from your requirements, there is no need to re-invent the wheel. FHIR allows you to create a new profile based on the base profile. For example, the Israeli CORE team (of which Outburn® is a proud member) created its own version of the Patient profile – ILCorePatient, which in turn inherits from the base profile. There are maybe a dozen differences between HL7’s Patient and ILCorePatient, namely several extensions (including the aforementioned HMO issue) and a number of Israeli-specific identifiers. A hospital which decides to use FHIR might want to add a few more hospital-specific data points but still conform to the Israeli standard. Bot a problem – they too can create a profile which inherits from the Israeli profile, which in turn inherits from the base profile. This means that if someone had already done most of the work, profiling becomes much easier – a clear advantage for FHIR!

Finally, FHIR is open source, so any resources created by countries or organizations are shared online. This means that any profile you might need might well already exist in a different organization and all you might need to do is look for it and make whatever tweaks necessary to make it fit your organization’s needs. This is another big advantage of moving to FHIR – reusability!


To summarize, base profiles are strict documents that allow for automatic interoperability by enforcing the exact same rules on any person or organization wishing to transfer information. Countries can then expand on the base profiles and add more country-specific extensions, change cardinalities etc. Finally, organizations may take any profile and extend it even further to meet its requirements, while still being able to maintain interoperability, thanks to the strict rules of the base profile.

Want to know more? In the coming weeks we will delve deeper into the nuts and bolts, the how and how not of profiling. In addition, we will cover alternative ways of producing your own profiles instead of the cumbersome, slow and error prone JSON or XML formats.

Feel free to contact us with questions you would like us to answer on our blog.

Don’t want to learn profiling yourself? Why not trust your project to the experts? Here at Outburn we will be happy to help you in all stages of your project, from the characterization stage, through profiling to the actual production of your FHIR artifacts.

(The image below shows a snippet of our favorite profiling tool – FHIR Shorthand – about which we will post in the near future!)

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FSH snippet

Follow us on LinkedIn and check out our academy page for information on courses and workshops!


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