# Alternatives to Postcoordination

Before you launch into a postcoordinated solution it’s important to understand that in some cases there are alternatives to postcoordination that may be easier to implement.

The two main alternatives to postcoordination are:

**Create extension concepts:**

* Firstly, and perhaps the most obvious alternative to postcoordination is to add the new clinical meanings to an extension, as precoordinated content. This approach enables the use of standard SNOMED authoring tools to classify the concepts and distribute them in a way that supports queries. However, this alternative is not an option for everyone, and in those cases, postcoordination may be considered.

**Use information model structure:**

* The second alternative is to define the postcoordination structure using the information model, using separate coded data elements for the focus concept, and each of the refinement values in the expression.\
  For example, rather than using an expression for ‘fracture of the foot’, two separate data elements could be applied, one for the SNOMED CT concept for 'fracture' and the other for the SNOMED CT concept for 'foot'. This approach has good accuracy for data capture but introduces significant limitations for the execution of semantic queries over the clinical data, as the focus concept is separated from the refinements and is not combined into a single SNOMED expression. In some situations where data is captured separately and follows the SNOMED CT concept model, post-processing can be applied to convert information models into postcoordinated expressions, after data capture.

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