Classes, Attributes and Relationships are components which together define the NHS Data Model. For further information, see Data Modelling.
A Class is something that you want to describe and the Attributes define the detail for the Class.
For example, the APPOINTMENT Class in the NHS Data Model describes an arrangement for a PATIENT to be seen by a CARE PROFESSIONAL.
The detail for the Class is defined by its Attributes, for example APPOINTMENT DATE, ATTENDED OR DID NOT ATTEND etc.
For further information on Attributes, see Attributes.
Has a Red Bar to signify that it is a Class;
Name is in UPPERCASE and where the name appears in text in RED, it indicates that it is a hyperlink and if clicked on will display the definition for that Class.
The following information is available on a Class:
"Description" tab: a definition of the Class which provides hyperlinks to other related definitions.
"Attributes" tab: the Attributes which are associated with that Class.
- A Key or a set of keys uniquely identifies an instance of a Class.
- The K before the Attribute name indicates that this is a key attribute of the Class.
- Attributes are sequenced with the key Attributes first.
- "Relationships" tab: the Relationship between Classes. For further information, see Relationships.
- The nature of the Relationship is indicated by:
- 'must be' if the Relationship is mandatory and
- 'may be' if the Relationship is optional.
- For further information, see Cardinality.
- Where Relationships from one Class to others are mutually exclusive, then 'or' appears at the beginning of the description between the second and subsequent exclusive Relationships. For further information, see Mutually Exclusive Relationships.
- A Key Relationship uniquely identifies an instance of a Class.
- Key Relationships are indicated by K before the relationship description.
- Relationships are sequenced with the key Relationships first.
"Where Used" tab: every item where the Class is used within the NHS Data Model and Dictionary.
What would you like to do next?
NHS Data Model and Dictionary Content
View Classes in the NHS Data Model and Dictionary.
For a demonstration on Classes, see the Classes Demonstration.
Please note that you will need flash player to view these demonstrations. If you do not have flash player, contact your organisation's technical support for further information.