Re: [Gnumed-devel] basic test types

[J Busser]

> The only proviso here is whether we can trust that two different 
> labs will never send us two results where each has the same (code, 
> coding system) but in fact the records represent two *different* 
> entities. I don't think this is possible unless the value in 
> coding_system is neither a standard (like LOINC) nor lab_specific 
> (like using the value in the FK_TEST_ORG key or the org name) but 
> instead something lax like "custom" or  "local" which *could 
> conceivably* be input manually by somebody.

Self-replying but...

further in the case where a lab might have supplied a code, but not a 
coding system (suppose it is their own internal coding system, so 
they do not bother naming it in their result) we might in the GnuMed 
test_type retain the default NULL for the coding_system but that 
would create a problem. So we should require NOT NULL and if the lab 
provides nothing we should assign to coding_system something to 
reflect the source lab's arbitrariness like using the value in the 
FK_TEST_ORG key, or else the org name, to convey "whatever unnamed 
system Lab Org X must evidently be using to assign their code".