DID YOU KNOW: There are multiple TYPES of FHIR IGs!

Dear OHIE Community,

In conversation with @bryn, we recently learned 2 important concepts:

  1. There are multiple TYPES of FHIR IGs (Implementation Guides).
  2. Content FHIR IGs are not the same as Model FHIR IGs.

There’s Currently Confusion about FHIR IGs in the Global Good & OHIE Communities

I notice across Global Goods we seem to be confusing one another when we just talk about “a FHIR IG” without clarifying the type of IG that we mean.

For example: I’ve had numerous conversations this year with other Global Good technicians saying “We are ready to integrate with OpenMRS because we have a FHIR IG” (they were not actually ready with the right type); or, where others have said to me “We don’t see how a FHIR IG will help our Global Goods be interoperable; a FHIR IG is only content guidance… right?” (Not necessarily! :wink: )

The Main Point: Global Good Integration through FHIR typically relies on one or more “Model IGs”, whereas the WHO’s SMART Guidelines L3 FHIR approach uses “Content IGs”.

The 2 Major Types of FHIR IGs You Should Know:

It’s really the first 2 that we should be aware of:

  1. Model IGs: These are like “Connect the Dots” toolkits, explaining “Here is how our system or standard uses FHIR.” For example, the International Patient Summary says “This is how a Patient Summary puts together immunization, medication and procedure history”. Even more specifically, the OpenMRS Model FHIR IG says “This is how our system’s data model converts our patient information into a FHIR patient resource”.


(I’m not aware of other Global Goods’ Model FHIR IGs but would love to know!)

Model IGs are quite powerful for in-country implementation teams who need to connect multiple Global Goods, and want to avoid the headache and overhead of having to learn and map the data models between Global Good A, B, and C. For example, UW ITECH found that once they had enough use-case coverage between the OpenMRS Model IG and the OpenELIS FHIR IG, the time for their team to set up integration between OpenMRS and OpenELIS went from 3-6 months to just ~2 days. Video demo of this here.

  1. Content IGs: Like a FHIR-ized Clinical Practice Guideline. These are effectively “Content Toolkits” that focus specifically on the content you would need in a particular use case or domain (e.g. ANC, HIV, etc), and then uses FHIR’s structure to organize that content. For example, medical terminology/codes/concepts are organized under a “valueSet” directory; whereas decision support rules and business logic are organized under the “planDefinitions” area.

Other IGs: There are other possible types of FHIR IGs, such as Specification IGs. These tell people what patterns to follow when they want to write detailed clinical guidance using the FHIR structure. Maybe not many of us will directly write a Specification IG ourselves, but we may use one to create a Content IG. For example, the Clinical Practice Guidelines IG has informed how subsequent Content IGs were written by the WHO SMART L3 Authoring team.

For More Information

More detailed examples (and this visual with more examples) available on the FHIR website here: Clinicalreasoning-knowledge-artifact-distribution - FHIR v6.0.0-cibuild

CC @costateixeira & @jennifer.e.shivers & @jthompson & @carl would love your help disseminating this important difference :slight_smile:
And a big thank-you to @costateixeira, @caseynth, and @pmankow for reviewing this post for accuracy in advance :pray:


Wow! this looks amazing. thanks @gracepotma for blending this.


Thanks @gracepotma I was in touch with @pmankow he suggested to come up with technical meeting on Smart Guidelines IG’s
CC: @costateixeira


Thank you @gracepotma. This is very insightful.


Hi everyone, and thanks @gracepotma for the opportunity to have this conversation.
I have been working in a FHIR IG about how a country has to specify a notification of a vaccine adverse effect to PAHO. We define a questionnaire and a questionnaireResponse FHIR resources and a few valuesets and even codesystems.
I don’t know how to categorize our IG.
I think that is a model IG, but it specifies a use-case and use valuesets as a content IGs. Is another type of IGs?
What do you think?
You may be wondering why this guy wants to categorize this IG?
The reason behind the categorization effort is to know if we can use the WHO SMART guidelines’ creation process as a guide or template.
Or our IGs are a type of IGs that do not allow this.

Thanks in advance for your feedback


Fantastic use case and questions @drmartindiaz! CCing @costateixeira as well to help if my answer is not on-point here…

It does sound like you have a bit of a hybrid, which is not necessarily wrong or bad! (Right, @costateixeira?)

When you say you’ve defined actual content like questionnaire content and specific valuesets, that fits with the Content IG “style”.

When you say you’ve also defined a structural / syntactic requirement on how the country needs to specify the notification, that sounds more Model IG-like.

@costateixeira do you see any major downsides to this hybrid approach? Would it be better to separate these into 2 distinct IGs?

Yes, I believe you can still use the SMART guidelines’ process as a guide, especially for the content pieces :slight_smile:


Dear @gracepotma thanks for this -

I’m trying to explain it to myself - are these statements correct?

Model IGs are GG-oriented making the GG FHIR-capable and ready to connect to other FHIR-capable GGs

Content IGs are business processes and data in FHIR format…

Love this thread…

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Great to see you here @amarcelo!! Happy new year!

Yes, I believe this is quite accurate :slight_smile:

I think you mean GG = Global Good, right? Model IGs are not inherently only for Global Goods; they can be used by any healthcare software, from open source to proprietary, from High-Income to Low-Income countries, etc etc. This is a huge part of why FHIR is so important: The potential for health data interoperability across all kinds of vendors and business models is huge.

Correct! At least, it’s the starting point :slight_smile: For example, at this moment, OpenMRS has a solid start in our Model IG, e.g. it can already be used to connect FHIR-friendly Lab Systems and MPI Systems (video demos here); however, there is no guarantee that any one Model IG covers exactly 100% of the FHIR standard. In fact, most software-specific Model IGs will only cover the use cases relevant to that software (e.g. you’d expect openIMIS to have more claim-related FHIR mapping than OpenELIS would), and may not be completely “finished”. E.g. we have been gradually building out the OpenMRS Model IG based on the real-world use cases our community immediately needed (which happened to be Labs and ID-related data sharing) but there’s more work and scope to add in over time :slight_smile: We actually strongly recommend this iterative approach as it seems some software orgs hold out on releasing their FHIR Model IG until they feel they’ve “covered everything”.

Hope this helps!

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