Help and guidance

Help, guidance and demonstrations relating to the content of the NHS Data Model and Dictionary.


The NHS Data Model and Dictionary is modelled using the following convention and naming:

  • Data Sets are built from a series of Data Elements and, optionally, groups of data elements.
  • Data Elements are a specialised use of Attributes for use within the context of the data set. For example they may introduce default codes applicable to a specific data element, perhaps to handle circumstances where data are not available.
  • Attributes describe the properties of Classes and provide common data definitions for classes. A class may in turn be a specialised form of another class (a subtype).
  • Classes describe aspects of the health and care business with their significant characteristics through their Attributes and their relationships to other Classes.
  • NHS Business Definitions describe specific applications of Classes within the context of the health and care system but don't introduce new attributes or relationships.
  • Supporting Information is not a part of the NHS Data Model but provides additional context for the reader.
  • XML Schema Constraints provide details of restrictions on the data permitted in XML schema for data sets.
  • Retired items are not included in the current definitions but are listed in the All Items Index.