How to find resource where identifier.system was not provided?

Seems a fairly basic question but I cannot find how to actually write the query.

For some reason, we have Patients where “system” in “identifier” is not set. Most of identifiers have the system correctly set but system is missing for some of them. I’d like to know how many are in this situation.

I can’t figure out what is search syntax?
This seemed encouraging but I’d like to not restrinct to any value
GET [base]/Patient?identifier=|2345
I’d need something like
GET [base]/Patient?identifier=|*
Does it exist?


I don’t think that there’s a standard search for identifier missing a system

Identifier uses the token search parameter. The syntax to search for a Coding or Identifier with no system is identifier=|12345

(Specific quote:

  • [parameter]=|[code]: the value of [code] matches a Coding.code or Identifier.value, and the Coding/Identifier has no system property