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Hospital Episode Statistics

Over 1 billion records of patients attending accident and emergency units, admitted for treatment or attending outpatient clinics at NHS hospitals in England. Hospital Episode Statistics (HES) data is available from four data sets, that is, Hospital Episode Statistics Admitted Patient Care (HES APC), Hospital Episode Statistics Critical Care (HES Critical Care), Hospital Episode Statistics Outpatient (HES OP) and Hospital Episode Statistics Accident and Emergency (HES A&E). For emergency care data from 1 April 2020, the Emergency Care Data Set (ECDS) should be requested.

Page contents

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Data set versions as presented in the DARS online system

  • Hospital Episode Statistics Admitted Patient Care (HES APC)
  • Hospital Episode Statistics Critical Care (HES Critical Care)
  • Hospital Episode Statistics Outpatients (HES OP)
  • Hospital Episode Statistics Accident and Emergency (HES A&E)

Access method

Data set available in packages

Packages are pre-defined groups of fields and or tables that allow a customer to select from a list that best meets their needs. Packages do not allow a customer to customise their field or table selection.

  • No 

Period of data coverage

  • Hospital Episode Statistics Admitted Patient Care (HES APC) 01/04/1989 ongoing
  • Hospital Episode Statistics Critical Care (HES Critical Care) 01/04/2007 ongoing
  • Hospital Episode Statistics Outpatients (HES OP) 01/04/2003 ongoing
  • Hospital Episode Statistics Accident and Emergency (HES A&E) 01/04/2007 to 01/04/2020

Geographical scope of data

England

Linkable to other data sets

  • Yes - Options for linking using pseudonymised data

Data collection process

Submitted by: NHS secondary care providers

Collected by: NHS England

Frequency: Monthly

Clinical coding systems

Does the data set include any standardised systems of coding?

  • ICD9, ICD10 (International Classification of Diseases classifies diseases and other health conditions.)
  • OPCS-4 (Office of Population Census and Surveys classification of interventions and surgical procedures.)
  • SNOMED-CT (a structured clinical vocabulary for use in electronic health records.)
  • TFCs (Treatment Function Codes are used to record treatment activities undertaken.)
Full list of coding systems considered

SNOMED-CT (a structured clinical vocabulary for use in electronic health records.)

ICD  (International Classification of Diseases classifies diseases and other health conditions.)

OPCS-4  (Office of Population Census and Surveys classification of interventions and surgical procedures)

dm+d  (Dictionary of descriptions and codes which represent medicines and devices in use across the NHS.)

NICIP (National Interim Clinical Imaging Procedure provides consistent recording of imaging procedures.)

UCUM  (Unified Code for Units of Measure (UCUM) is a code system intended to include all units of measurement.)

TFCs (Treatment Function Codes are used to record treatment activities undertaken)

Read Code v2  (A coded thesaurus of clinical terms.)

Read Code Clinical Terms v3 (A coded thesaurus of clinical terms.)

UICC (Union for International Cancer Control classification of cancer by anatomic disease extent.)

IMD  (Indices of Multiple Deprivation measures relative poverty.)

Derived fields

Standardised formulation may be applied across multiple data sets to generate commonly derived fields.  Any standard derivations applicable to this data set are listed below. Please note that this does not include bespoke derivations created specifically for the individual data set.

  • CCG_OF_RESIDENCE (Clinical Commissioning Group covering the area in which the patient’s postcode falls where data relates to pre 1 July 2022. Otherwise ICB Sub Location.)
  • LA_OF_RESIDENCE (The Local Authority covering the area in which the patient’s postcode falls.)
  • LSOA_OF_RESIDENCE (The Lower Super Output Area (lowest level without being disclosive) covering the area in which the patient’s postcode falls.)
  • CCG_OF_REGISTRATION (Clinical Commissioning Group which has a commissioning relationship with the GP Practice which the patient is registered at where data relates to pre 1 July 2022. Otherwise ICB Sub Location.)
Full list of standard derivations considered

GP_PRACTICE_CODE_TRACED (The GP Practice that the patient is registered at, as found when traced against the Person Demographic Service (PDS).)

CCG_OF_RESIDENCE (Clinical Commissioning Group covering the area in which the patient’s postcode falls where data relates to pre 1 July 2022. Otherwise ICB Sub Location.)

ICS_OF_RESIDENCE (The Integrated Care System covering the area in which the patient’s postcode falls. This will be null for any data relating to earlier than 1 July 2022.)

LA_OF_RESIDENCE (The Local Authority covering the area in which the patient’s postcode falls.)

LSOA_OF_RESIDENCE (The Lower Super Output Area (lowest level without being disclosive) covering the area in which the patient’s postcode falls.)

CCG_OF_REGISTRATION (Clinical Commissioning Group which has a commissioning relationship with the GP Practice which the patient is registered at where data relates to pre 1 July 2022. Otherwise ICB Sub Location.)

ICS_OF_REGISTRATION (The Integrated Care System covering the area in which the patient’s GP Practice falls. This will be null until for any data relating to earlier than 1 July 2022.)

LA_OF_REGISTRATION (The Local Authority covering the area in which the patient’s GP Practice falls.)

LSOA_OF_REGISTRATION (The Lower Super Output Area (lowest level without being disclosive) covering the area in which the patient’s GP Practice falls.)

Third party licensing

Does the data set require copyrighted clinical assessment tools or outcome measures that require a licence?

  • None

Advice and support

Governance of this data set is provided by:

Owning organisation: NHS England

Data Controller: NHS England

Data Processor: NHS England

NHS England provides a variety of functions for the data sets we make available.  Therefore, our knowledge and understanding of the data will vary, impacting the level of advice and support we can provide.

In relation to this data set, we undertake end to end management and can therefore provide a full advice, guidance and support service.

Supporting documentation and guidance

ARTICLE

Commissioning Data Sets

Commissioning Data Sets (CDS) enable national reporting on NHS funded or provided secondary care.
ARTICLE

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.
ARTICLE

Metadata dashboard

This dashboard provides metatdata on publicly available fields for available data sets.
ARTICLE

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.
ARTICLE

CDS DQ Dashboards

This Dashboard shows data quality and completeness of the Commissioning Data Sets which is used to support the development of HES.

Last edited: 31 January 2025 12:00 pm