Stream: conformance
Topic: naming system conventions
Simone Heckmann (Apr 15 2016 at 12:31):
I am still uncertain about the best practice as far as naming systems are concerned: We established that assigning urls which one doesn't control is not a good idea, so we tend to assing http://hl7.de/fhir/...-urls to any Germany-specific identifier namespace we need for our profiles. This has the additional benefit that we can redirect these urls to pages in our wiki that explain the correct usage of these identifiers. How do other affiliates handle this?
Michel Rutten (Apr 15 2016 at 12:39):
I agree that an organization should control the domains of all the canonical url's that it assigns.
Michel Rutten (Apr 15 2016 at 12:40):
In Holland, we will probably use base urls controlled by different national organizations, such as hl7.nl and nictiz.nl.
Simone Heckmann (Apr 15 2016 at 12:59):
For namespace "xyz" assigned by a FHIR-agnostic national organization "abc" would you use "http://hl7.nl/xyz" or "http://hl7.nl/NamingSystem/xyz" or "http://hl7.nl/NamingSystem/abc/xyz"
Simone Heckmann (Apr 15 2016 at 13:11):
I also wonder, if there should be a convention on how to assign an organization's internal identifiers, e.g. the Patient identifier in a Hospital...
Say we have a Patient with the identifier "123" in hospital "http://myHospital.com".
should it be
"http://myHospital.com/fhir/Patient/" or
"http://myHospital.com/fhir/Identifiers/Patients/" or
"http://myHospital.com/Patient-Identifiers/" or something completely different?
It probably doesn't really matter, as long as the urls are unique, but I keep stumbling over that decision every time, so I think it could be helpful do propose a scheme...
I see a potential danger in people just using "http://myHospital.com/" and later realize that they have overlapping identifiers for Patients, Orders and Users all under the same Namespace, so I'd consider something like "http://<myDomain>/fhir/<ResourceType>" a sound advice.
Michel Rutten (Apr 15 2016 at 13:28):
I guess it depends on the intended/expected re-use. If an identifier will never be used outside of an organization, then you could use the organization domain in the base url. But if an identifier is used by multiple organizations it may be better to use a regional or national domain as the base url. Also, by convention, a canonical url is of the form [domain]/fhir/[resourcetype]/id.
Michel Rutten (Apr 15 2016 at 13:30):
If an organization controls a domain, then I'd suggest to use that domain as the base url. However if that is not feasible, then you could fall back to another national domain such as hl7.de.
Simone Heckmann (Apr 15 2016 at 13:30):
So it would be wise to apply the canonical scheme to identifier systems as well...
Michel Rutten (Apr 15 2016 at 13:30):
For all canonical url's, I'd suggest you stick to the canonical scheme.
Michel Rutten (Apr 15 2016 at 13:31):
i.e. include resourcetype
Simone Heckmann (Apr 15 2016 at 13:32):
That information should go somewhere near this place: http://hl7-fhir.github.io/datatypes-definitions.html#Identifier.system
Lloyd McKenzie (Apr 15 2016 at 13:34):
For Canada, I'm leaning toward http://hl7.org/fhir/NamingSystem/ca-[whatever], but that's because we don't have an hl7.ca domain to use (nor a registry sitting there). I think having the URL resolve to the NamingSystem is useful because it lets you maintain the NamingSystem to point to the current/best URL for that particular identifier type - and I have little trust in the websites associated with most identifier types remaining static or creating re-directs.
Simone Heckmann (Apr 15 2016 at 13:41):
Ok, so we'd use http://hl7.de/fhir/NamingSystem/<IdentifierName>.
And for a hospital's internal patient identifiers it would be
http://myHospital.org/fhir/NamingSystem/PatientIdentifier
Michel Rutten (Apr 15 2016 at 13:42):
That seems to be the preferred approach.
Simone Heckmann (Apr 15 2016 at 13:43):
I don't think many of the examples reflect that ;-)
Michel Rutten (Apr 15 2016 at 13:45):
Well I guess it's not mandatory, just good practice. Maybe FHIR could provide some guidance and/or concrete examples from different countries.
Lloyd McKenzie (Apr 15 2016 at 18:34):
Someone want to raise a change request? :)
Grahame Grieve (Apr 15 2016 at 19:27):
"For Canada, I'm leaning toward http://hl7.org/fhir/NamingSystem/ca-[whatever]" - which will make Canada a hostage to FHIR publishing cycles. I'm not sure that's what you want
David Hay (Apr 15 2016 at 19:36):
I was thinking of fhir.hl7.org.nz/NamingSystem/[whatever] - where fhir.hl7.org.nz is our registry...
Lloyd McKenzie (Apr 15 2016 at 19:37):
@Grahame Grieve Only for the full resolution piece. The registry would work right away. Right now, there isn't an hl7.ca domain and I'm not sure Infoway has the resources/interest to maintain it.
Josh Mandel (Apr 15 2016 at 19:38):
+1 for decoupling...
Grahame Grieve (Apr 15 2016 at 19:39):
it doesn't have to be infoway. you can do what other countries are doing and just use a wiki / fhir server (there's a few free ones around)
Lloyd McKenzie (Apr 15 2016 at 20:14):
Infoway is the holder of HL7 Canada and have the resources to make it happen. Not sure it would fly if someone just took it on on a volunteer basis.
Ewout Kramer (Apr 18 2016 at 11:34):
+1 for decoupling...
Well, more and more these canonical urls become uri's I think - for true decoupling they should maybe NOT be resolveable. You could then ask any registry using a search for a ValueSet with a given uri.
Grahame Grieve (Apr 18 2016 at 11:34):
then you might a well use oids
Grahame Grieve (Apr 18 2016 at 11:35):
because it isn't ask 'any registry' it's ask 'every registry'
Ewout Kramer (Apr 18 2016 at 11:37):
Well, you could use uri's that are structured like openEHR archetype names. Have you had experience with using these on scale in AU?
Grahame Grieve (Apr 18 2016 at 11:55):
no
Josh Mandel (Apr 18 2016 at 13:27):
Good URLs are still readable, even if they're not dereferenceable.
Last updated: Apr 12 2022 at 19:14 UTC
