We have detected that you are using Internet Explorer to visit this website. Internet Explorer is now being phased out by Microsoft. As a result, NHS Digital no longer supports any version of Internet Explorer for our web-based products, as it involves considerable extra effort and expense, which cannot be justified from public funds. Some features on this site will not work. You should use a modern browser such as Edge, Chrome, Firefox, or Safari. If you have difficulty installing or accessing a different browser, contact your IT support team.
Hospital Episode Statistics Data Dictionary
The Hospital Episode Statistics (HES) Data Dictionary is intended for use by all users of HES data. Data dictionaries work in the same way as normal dictionaries, but they contain information about data items.
The HES Data Dictionary contains detailed information on the fields from the admitted patient, outpatient, accident and emergency and adult critical care data sets that are collected and used in HES and the Patient Reported Outcome Measures (PROMs) data set. These include those submitted directly by the data providers and also fields we derive and add to the data sets.
The HES Data Dictionary also identifies which cleaning or derivation rules have been applied to which fields. The cleaning rule definitions, used in conjunction with the HES Data Dictionary, are available on the processing cycle and HES data quality page.
NHS Data Model and Dictionary
The fields within HES are either based on or derived from the NHS Data Model and Dictionary. This covers all data sets and data items used in the NHS, not just those from which HES is extracted. It is developed and maintained by the NHS Data Model and Dictionary Service at NHS Digital.
Please send any data dictionary queries to enquiries@nhsdigital.nhs.uk referencing HES Data Dictionaries in the subject
Retired fields
From April 2021 a number of fields are scheduled for retirement from the Hospital Episode Statistics (HES) data as part of the changes to HES. A list of these fields can be found in the document below and further information is also available in the HES data dictionaries.
Download HES Data Dictionaries
-
asset
HES Data Dictionary - Accident and Emergency [pdf, size: 1.6 MB]
-
asset
HES Data Dictionary - Admitted Patient Care [pdf, size: 2.5 MB]
-
asset
HES Data Dictionary - Outpatients [pdf, size: 1.7 MB]
-
asset
HES Data Dictionary - Adult Critical Care [pdf, size: 2.5 MB]
-
asset
HES Data Dictionary [xlsx, size: 208.5 kB]
-
asset
HES APC Data Dictionary supplementary table [xlsx, size: 61.9 kB]
-
asset
Data Dictionary - HES-ONS linked mortality data [docx, size: 704.7 kB]