The data model is the part of the ontology that defines classes required for particular business purposes.
Business purposes vary from the need to store particular items of data through the need to display items in a certain way. This is the model that defines the ever evolving structure of health records held within multi-domain health records, varying from common high level classes through to specialised classes. An example of the former is an 'observation', and an example of the latter is a 'histological/immunological report on a breast carcinoma'. in IS013606 these are called archetypes and their derivative templates.
Whilst the data model supports inheritance (in the ways described below), unlike the semantic ontology, the data model classes are not inherently semantically defined in relation to other concepts. In order to semantically define a data model class, a special property 'is of type' is used to link the semantic definition to the data model. This is described below.
The data model is built using the same OWL2 information modelling language as the semantic ontology. A major difference is the way in which the two are used. In the case of a data model, an application would use a 'closed world assumption' with the use of query language to filter and sort, whereas in the semantic ontology an application would use the 'open world assumption' with the use of reasoners to enable subsumption testing.
Data model classes often use terms that appear to have meaning that should be semantically defined, therefore a convention used is to identify the different concepts by the use of a () qualifier.
For example a data model class of 'encounter' would be named 'Encounter (data model)' whereas the encounter class that holds it's semantic definition may be called 'Encounter (type)'. (The qualifier 'type' is often omitted for brevity)
For example, An accident and emergency encounter (data model) -> is of type -> 'Accident and emergency'. This separation allows for many more types than there are data model entities. For example a 'Consultation (data model)' -> is of type-> Telephone triage consultation' as there may be no difference in the business properties. On the other hand, if there was a business purpose to record the 'quality of the call' in a telephone triage consultation, then a 'Telephone triage consultation (data model)' concept would be created as a subclass of 'Consultation (data model)'
Model content
main article Discovery health data model
In line with the information model itself, the model content is constantly evolving. These articles provide an overview of content at a particular point in time, as high level background. There is likely to be a discrepancy between the documentation on this wiki and the information model itself. The model content is best viewed via the information model viewer, although the viewer itself may also reference the wiki.