About the NHS Data Dictionary

About the NHS Data Dictionary Version

Link to the NHS Data Dictionary Version 3.0

Following the issue of DSCN 07/2004 'Data Standards: Meta Model'; the NHS Data Dictionary has been changed to reflect and be based upon a more generic logical data model which will better support the strategic way forward. This NHS Data Dictionary will be published as the NHS Data Dictionary Version 3.

There has been extensive quality assurance of Version 3 including involvement of the Data Definition Group. All Version 3 contents have been cross mapped and checked to ensure consistency with the current Version 2 contents. With the completion of the final quality assurance, Version 3 is now ready for live publication and will completely supersede the current Version 2 on 1st May 2005.

Version 3 supports all the messages, datasets and central returns supported by Version 2 but the underlying structure has been genericised. No changes have been made to business definitions.

Version 3 introduces a new UML (Unified Modelling Language) Generic Model which is 'person based' rather than 'organisation based'. The model has been developed around generic 'care activity' for a patient at 'service point' facility or location with each event transaction being recorded. This has involved grouping many of the old classes into generic classes like ACTIVITY GROUP. However, none of the detail or approved definitions or value sets in Version 2 has been lost although some of the old class definitions will now be found in the new 'NHS Business Definitions'.

The NHS Data Dictionary Version 2 will be frozen and made available for archive information purposes only and will be watermarked accordingly. All future changes to NHS data standards and the supporting DSCNs will be made or be consistent only with Version 3.

Summary of main changes and enhancements incorporated within Version 3

• Introduction of the capability of holding Retired Items
• Introduction of NHS Business Definitions, which allow specific business areas to be defined in a more flexible manner
• New ‘All Items Index’ which lists all the contents held within the Data Dictionary
• Reduction in the number of data model diagrams making them more comprehensible
• Introduction of Domains, which are conceptual logical modelling objects which identify the logical format, length and value set attributable to one or more attribute/s
• Where Used list expanded to include a description of usage column
• Creation of a separate Meta Model area within the publication

The introduction of Version 3 has no impact on current data standards or system suppliers.

About the Generic Model

We have been working on supporting the principles of RoWBI (Review of Waiting and Booking Information), the emerging Secondary Uses Service (SUS), the national data warehouse and the migration of the CDS messages. This has included rationalising the existing data standards so that the NHS Data Dictionary can support both the 'legacy' systems and data needs, as well as new and emerging systems and data needs.

It supports all the messages, datasets and central returns which the current model supports but the underlying structure has been genericised. This has involved grouping many of the old classes into generic classes like ACTIVITY GROUP. However, none of the detail has been lost and most of the old class definitions can be found in the new 'Business Definitions'. The number of diagrams has been greatly reduced and they now describe coherent areas of the model which is a far more useful approach for data modellers.

This has led to the creation of a new UML (Unified Modelling Language) Generic Model which is 'person based' rather than 'organisation based'. The model has been developed around generic 'care activity' for a patient at 'service point' facility or location with each event transaction being recorded.

The Model will form the underpinning common structure which can be used by all future datasets related to patients and care activity, whether they be 'administrative', 'clinical', 'management' etc. The data elements specified within the model and within attached dataset modules will form the basis for XML message exchanges.

The model is aimed at enabling all 'care activities' related to the same condition for the same patient to be recorded and linked across organisations. The different states of the same 'care activity' are recorded as event transactions e.g. requested, intended, scheduled, provided, cancelled, etc. These different state events also drive the scheduling and capacity planning of resources (people, equipment, facilities, etc.) to deliver the care.

Contact us for more information: For more information contact the NHS Data Model and Dictionary Service

The NHS Data Dictionary gives common definitions and guidance to support the sharing, exchange and comparison of information across the NHS. The common definitions, known as data standards, make up the base currency of Commissioning Data Sets (CDS), and on the monitoring side, they support comparative data analysis, preparation of performance tables, and data returned to the Department of Health.

NHS data standards also support clinical messages, such as those used for pathology and radiology.

NHS data standards also have an important role in supporting the flow and quality of information used in different parts of the NHS so that health care professionals are presented with the relevant information where and when it is required. An example of this is the linking of all records about a patient collected in different parts of the NHS, to be available to a care professional wherever the patient attends to be seen for treatment, thus facilitating the Electronic Patient Record.

NHS data standards are presented as a logical data model, ensuring that the standards are consistent and integrated across all NHS business areas, and changes to the contents of the NHS Data Dictionary are published as Data Set Change Notices (DSCNs).