A qualifying characteristic is expressed by an attribute-value pair. The attribute may have one value, from a range of values, based on the domain's concept model. If a particular qualifying characteristic is applied to a concept, the resulting expression represents a more tightly defined subtype of that concept.
Clinical expressions using SNOMED CT concepts can be of two types: precoordinated expressions, which use a single SNOMED CT concept identifier; and postcoordinated expressions, which contain more than one SNOMED CT concept identifier.
- It might be possible to qualify a disorder such as 53084003 | Bacterial pneumonia (disorder)| according to its clinical course ( 373933003 | Acute onset (qualifier value)| or 90734009 | Chronic (qualifier value)| ) or severity ( 255604002 | Mild (qualifier value)| , 6736007 | Moderate (severity modifier) (qualifier value)| , or 24484000 | Severe (severity modifier) (qualifier value)| )
- 125605004 | Fracture of bone (disorder)| can be refined by qualifying it with 12611008 | Bone structure of tibia (body structure)| to represent the concept 31978002 | Fracture of tibia (disorder)|