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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 all critical care data sets that are collected and used in HES and may also be used in data sets that utilise HES such as the Patient Reported Outcome Measures (PROMs) data set. These include those data submitted directly by the data providers and also fields we derive and add to the data sets.
Changes to HES Data Dictionary 2021
From September 2021 NHS Digital has made changes to the way we process the HES data set.
To support these changes NHS Digital has updated and consolidated, where possible, how we disseminate both detail from the HES Data Dictionary and other related supporting documentation into a single place. This being the new HES Technical Output Specification document found on this webpage: This document replaces our historical HES data dictionary documents and also our HES auto cleanse data dictionary.
Details of fields with data quality issues are also available in this document, under the ’Known Data Item Issues’ tab
The HES ONS linked data dictionary remains available and will be updated in the coming weeks.
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.