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Hospital Episode Statistics (HES)

Hospital Episode Statistics (HES) is a curated data product containing details about admissions, outpatient appointments and historical accident and emergency attendances at NHS hospitals in England.


Improving how we use data to support the NHS was a key theme highlighted in the Data Saves Lives policy paper. HES data supports services like the NHS England Cohorting as a Service, and also research and innovation to power new medical treatments through services like the DigiTrials service. This is reflected in increased use of HES by customers for purposes relating to the direct care of individuals.

HES provides data for the purpose of healthcare analysis to the NHS, government and others including:

  • national bodies and regulators, such as the Department of Health, NHS England, Public Health England, NHS Improvement and the CQC
  • Integrated Care Boards (ICBs) 
  • provider organisations
  • government departments
  • researchers and commercial healthcare bodies
  • National Institute for Clinical Excellence (NICE)
  • patients, service users and carers
  • the media

Through the increasing multiple use of HES the ongoing benefits provided by such a clearly defined data product is clear.

HES can be used for:

  • monitoring trends and patterns in NHS hospital activity
  • assessing effective delivery of care
  • supporting local service planning
  • providing the basis for national indicators of clinical quality
  • revealing health trends over time
  • informing patient choice
  • determining fair access to health care
  • developing, monitoring and evaluating government policy
  • supporting NHS and parliamentary accountability
  • national policy making
  • benchmarking performance against other hospital providers or ICBs 
  • academic research
  • analysing service usage and planning change
  • providing advice to ministers and answering a wide range of parliamentary questions
  • national and local press articles
  • international comparison

About the data product

HES data covers all Sub Integrated Care Boards (Sub ICB) and Integrated Care Boards (ICB) in England (previously Clinical Commissioning Group, CCG), including:

  • private patients treated in NHS hospitals
  • patients resident outside of England
  • care delivered by treatment centres (including those in the independent sector) funded by the NHS

Each HES record contains a wide range of information about an individual patient admitted to an NHS hospital, including:

  • clinical information about diagnoses and operations
  • patient information, such as age group, gender and ethnicity
  • administrative information, such as dates and methods of admission and discharge
  • geographical information such as where patients are treated and the area where they live

Details of all the data fields that are present within HES with additional detail pertaining how they were derived or processed may be found within the HES Analytical Technical Output Specification.

In providing a data product that supports the different requirements of its customers, HES also ensures that requirements of people described by the data are met through pseudonymisation, data minimisations and also through adherence to disclosure control rules around the reporting of aggregate outputs produced using the data. Further detail on these reporting rules may be found in the HES analysis guide.

Historically HES has been used for non-clinical purposes, such as research and planning health services. Because these uses are not related to direct patient care, they are called 'secondary uses'.

The Emergency Care Data Set (ECDS) is the national data set for urgent and emergency care, following a phased transition in reporting to the ECDS that commenced in October 2017. It replaced the HES Accident and Emergency Commissioning Data Set in April 2020.

HES does not include all mental health specific hospital activity, as Mental Health providers are required to submit this activity to the Mental Health Services Data Set (MHSDS).

Data collection

The HES data product is created from data submitted to NHS England as part of the Commissioning Data Sets (CDS) which is managed by the Secondary Uses Service (SUS+). At pre-arranged dates during a specific financial year, SUS takes a fixed snapshot of the CDS of cumulative activity recorded up to that point within that financial year.

This is then subject to additional processing to create a curated data product that is appended to finalised historical data that has been processed for previous years. Detail of the additional processing that occurs to create HES can be found on the Processing cycle and HES data quality page and the HES Technical Output Specification. HES has been designed to support ongoing business needs for many organisations with multiple user requirements.

Each extract is cumulative and contains data submitted for the financial year so far, that is to say, month 1 will only contain the data submitted with an activity date in April, but month 6 will contain data submitted with an activity date from April to September. One of the reasons for this is that additional data may be needed to update patient records from earlier in the year. For example, an episode may potentially run for several months, or an amendment may need to be made as clinical coding takes place on discharge.

HES data is a snapshot of data taken on the Reconciliation and Post-Reconciliation dates for each month. The SUS database is continually updated so the totals in SUS for a month will only match HES if they are queried on the day the snapshot is taken.

Annual refresh and final year data

At the end of each financial year we produce the official publication for that year. This is based on the March Post-Reconciliation submissions, also called Month 13.

While data relating to episodes and spells for a particular year can be amended and updated in SUS long after the year has passed, no further SUS updates are applied to HES which is fixed after the Post-Reconciliation Inclusion date for March

Accessing Data

In addition to the standard analyses published by NHS England, certain users can also access data via the:

  • Data Access Request Service (DARS) - available on request to a wide range of customers, including researchers, academia and arm's length bodies subject to an appropriate user case and legal basis.
  • Data Access Environment (DAE) - approved users can access NHS data to perform analysis
  • Monthly Managed Extract Service (MMES) - users receive an extract from HES on a monthly basis

If you request access to patient level data you may have to meet certain criteria before we'll consider your application.

See Access to Hospital Episode Statistics for further information including access to the HES Data Extract Service.

Analytical Technical Output Specification and Data Dictionary

The Hospital Episode Statistics (HES) Data Dictionary is intended for use by all users of HES data. An NHS data dictionary works in the same way as a normal dictionary but contains information about data items.


The HES data product is used to create a wide range of analytical and statistical outputs across many different organisations and teams. To support this activity NHS England produce the following monthly and annual official statistic reporting series which are available from the NHS England website.

Monthly HES publications

Monthly Accident and Emergency Quality Indicators

Annual HES publications for:

If you are interested in utilising HES data to support a specific need that may not be addressed through the content of our official statistics published outputs above then it is possible to apply for other standard and bespoke extracts using our Data Access Request Service.

Data protection

Hospital Episode Statistics (HES): GDPR

Why and how we process your data within Hospital Episode Statistics (HES) services, and your rights.

Data protection impact assessment support for Information Asset Owners (IAOs)

Information Asset Owners (IAOs) can use the information in this section to help them complete the data protection impact assessments (DPIAs) for the assets they own.

Disclosure control methodology for Hospital Episode Statistics (HES) and Emergency Care Data Set (ECDS)

The methodology will be applied by the Secondary Care Analysis team in producing and disseminating outputs using Hospital Episode Statistics (HES) and Emergency Care Data Set (ECDS) data.

Data Provision Notice

HES data is sourced from the Secondary Uses Service (SUS+) submission and comes under the Data Provision Notice for Commissioning Data Sets. More information can be found on the Commissioning Data Sets Data Provision Notice page.

Further information

internal Payment by Results

Payment by Results (PbR) is a system of paying NHS healthcare providers a standard national price or tariff for each patient seen or treated.

internal The processing cycle and HES data quality

Hospital Episode Statistics (HES) data comes from the routine submissions of data from providers to NHS Digital for the purposes of payment for and commissioning of healthcare in England.

internal Hospital Episode Statistics data changes from 2021

From September 2021 we made changes to the way we process the Hospital Episode Statistics (HES) data set. These improvements provided data users with the tools to process larger volumes of data and manage incoming data to ensure that it is accurate, useful and secure.

internal Artificial data pilot

Artificial data sets provide users with large volumes of data that share some of the characteristics of real data while protecting patient confidentiality. They are designed to model the structure of real data but are completely artificial – they do not contain any actual patient records.

Last edited: 19 February 2024 11:06 am