Current Version - Under Revision
SNOMED CT, enables the use of
postcoordinated expressions to represent detailed clinical information (such as observations or procedures) by
reference to multiple
Concept Identifiers .
When considering migration of existing data an important question is whether postcoordination is required to replace existing coded data. The answer to this question depends on the specificity and expressivity of the existing coding scheme.
There are four situations in which postcoordination may be required or useful in the mapping process.
Example: Information coded using NHS Clinical Terms Version 3, may also include postcoordination using qualifiers. In most cases, these qualifiers can be represented using postcoordinated expressions .
Example: A specialized radiology coding systems may have separate codes for the same procedure applied to different body sites. If SNOMED CT does not include these, they can be represented using postcoordinated expressions with 'procedure site' and 'laterality' Attributes applied.
Example: A system may have a separate field for laterality and this can be applied during the mapping process to generate a postcoordinated expression .