hi William There is plenty of health informatics science that tells that combining data from various systems is only possible when each data element is uniquely coded.
That single use case alone - reusing data from multiple systems - justifies the SHALL linkage between data element/node and terminology as Snomed CT. I generally find that only 5% of my data elements have an appropriate code in snomed. Sometimes I can find a general code that can be used as the code for the field, but it's actually the root code for the set of values that is the answer. That's not the same as the code for the field. And I think that given the sparseness of Snomed-CT for elements, that the granularity of the available codes is too coarse to even detect subtle mismatches between different systems. Though I do very much *wish* that what you say was possible Grahame
