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.