Stream: implementers
Topic: Coding.system values
Brian Reinhold (Nov 06 2018 at 09:51):
I have become terribly confused on how to specify the Coding.system element. For example, in the Observation.category the code system (used) to be
- http://hl7.org/fhir/observation-category
Now its either http://hl7.org/fhir/ValueSet/observation-category or is it http://terminology.hl7.org/CodeSystem/observation-category? Do I have a choice? What if I only use codes from http://terminology.hl7.org/CodeSystem/observation-category?
Lloyd McKenzie (Nov 06 2018 at 13:54):
System can't ever be the URL for a value set. We've shifted from FHIR-specific terminology to generic terminology (sharable with v2, v3 and CDA) for a number of our code systems in R4. There's no choice. It'll be http://terminology.hl7.org/CodeSystem/observation-category
Lloyd McKenzie (Nov 06 2018 at 13:55):
If you see anything else in examples or somewhere else that suggests otherwise, please yell.
Brian Reinhold (Nov 06 2018 at 14:01):
If you see anything else in examples or somewhere else that suggests otherwise, please yell.
It might be helpful to have more clear text on the issue, fox example in Coding.system that the value must always refer to a code system and not a value set. When I click on 'Observation Category Codes (Preferred)' viewing the Observation resource the first thing I see in bold text is
Value Set http://hl7.org/fhir/ValueSet/observation-category
One is tempted to use that since the codes one might use will come from this value set.
Lloyd McKenzie (Nov 06 2018 at 14:08):
We try to make that clear in the page that talks about terminology. There's no way to avoid having the value set URL prominent on the value set page because that's what you need to link to the value set. We do list the code system URL once we start to get to the codes
Rob Hausam (Nov 06 2018 at 15:28):
The first sentence here states that clearly. This page is also the first link under Documentation in the terminology module. I may look at trying to make that even more prominent when I make the terminology module updates that are still planned for R4.
Last updated: Apr 12 2022 at 19:14 UTC
