Stream: catalogs
Topic: Differences between Catalogs and CodeSystems
Lin Zhang (Apr 04 2021 at 12:56):
What are the differences between Catalogs and CodeSystems?
Lin Zhang (Apr 04 2021 at 12:57):
Specific/specialized vs. Generic/generalized?
Lin Zhang (Apr 04 2021 at 13:08):
I got pretty much help from the IG, such as its Section 1.5 Scopes of order catalogs and roles involved (https://build.fhir.org/ig/HL7/fhir-order-catalog/index.html#scopes-of-order-catalogs-and-roles-involved).
François Macary (Apr 08 2021 at 13:31):
CodeSystem resources hold and describe coded concepts covering a particular domain, whereas catalogs hold services, products or other artifacts useful for healthcare. The descriptions of those artifacts, use coded concepts coming from various Code Systems.
Lin Zhang (Apr 08 2021 at 13:49):
@François Macary Appreciate that. Abstract concepts/entities vs relatively concrete entities (but not completely concrete instances), right?
François Macary (Apr 08 2021 at 14:03):
Not sure what you mean by "discrete". Another way to see it is that CodeSystems provide concepts, which are useful to populate codeable elements of resources. Among those resources are the resources that represent healthcare services (PlanDefinition), knowledge artifacts (PlanDefinition again), devices (DeviceDefinition), products (MedicationKnowledge). All these resources include CodeableConcept elements, that are populated with concepts coming from various code systems. And catalogs are repositories of such resources.
Lin Zhang (Apr 08 2021 at 16:14):
Very sorry, I mean concrete.
Lin Zhang (Apr 08 2021 at 16:22):
Well, now I am understanding the difference better. If my understanding is right, Catalogs are repos of those resources just before they become instances in real events/encounters etc.
Lin Zhang (Aug 24 2021 at 09:03):
Should RxNorm be loaded as a Catalog or a CodeSystem?
Lin Zhang (Aug 24 2021 at 09:06):
A wierd question, right?
François Macary (Aug 24 2021 at 10:37):
RxNorm is a CodeSystem listed in the Terminologies tab of the FHIR standard and this page further describes how to use it as a CodeSystem in FHIR. It is a rich terminology, with lots of properties, but yet, still a CodeSystem.
Lin Zhang (Aug 24 2021 at 15:26):
Yes, indeed. Is it a mixture of CodeSystem and Catalog? There are brand names if I'm right.
François Macary (Aug 24 2021 at 17:12):
It is a national code system for the US, describing drugs authorized on the US market.
Lin Zhang (Aug 25 2021 at 23:56):
@François Macary Appreciate it. You're right. In other words, my question is how to distinguish these two kinds of Resources.
Jose Costa Teixeira (Aug 26 2021 at 12:34):
I'd say if you want to provide a list of codes eventually with some hierarchical relations - codesystem should be fine.
If you want to describe the actual items - from composition, to prescribing rules, pricing info, origin, testing and recall status etc - then you need a set of resources
And if you want that list of characteristics to be authored/authoritative (e.g. "ACME Hospital's 2021 allowed products and devices for por usage in the OR", then you need something like a Catalog that puts those together
Lin Zhang (Sep 01 2021 at 00:15):
@Jose Costa Teixeira Thanks. Actually, I didn't get it completely. I think, CodeSystem could be used to represent a national formulary. Apparently, I'm wrong by the spec. But why?
Lloyd McKenzie (Sep 01 2021 at 00:17):
Typically a formulary isn't defining its own codes. You could make a value set that defines all of the codes in your formulary, but a formulary typically wants to introduce additional concepts, like when a drug can be used, what tier it's in, what portion will be paid for, etc.
Lin Zhang (Sep 01 2021 at 00:21):
@Lloyd McKenzie Yes, it's not defining codes. Maybe, concept properties could be used to describe such additional things.
Lloyd McKenzie (Sep 01 2021 at 00:49):
Concept properties are limited. They can't be references. They're only one level deep. Plus the properties can't be added by value sets, only code system supplements. The properties would be different for the same drug for different formularies. It might be good enough in some cases, but not great for general use.
Lin Zhang (Sep 01 2021 at 23:52):
@Lloyd McKenzie Thank you so much. My understanding is much better now.
Last updated: Apr 12 2022 at 19:14 UTC
