Hospital Episode Statistics (HES)
What Is HES?
Hospital Episode Statistics (HES) is a database containing details of all admissions to NHS hospital trusts in England (including acute hospitals, mental health, primary care trusts and mental health trusts). This includes inpatient, daycare, maternity and mental health records. It does not currently include outpatients or Accident and Emergency (A&E) records. Although comprehensive data on treatment in private hospitals is not included, HES does include information on care provided to NHS patients by the independent sector and care given to private patients in NHS hospitals.
What Information Is Included In HES
HES currently contains a wide range of information. It includes demographic information about people admitted to hospital including age, sex, place of residence and ethnicity. It includes information about the reason for admission such as diagnoses (ICD-9 and ICD-10 coded ) and procedures ( OPCS-4 coded ) carried out along with information about how and where the patient was admitted. A full list of information collected can be viewed in the HES Data Dictionary.
Data are available for every financial year from 1989-90 onwards. In 2004-05 there were 12.1 million admissions, resulting in nearly 14 million records.
What Is HES Used For?
HES is the data source for a wide range of healthcare analysis for the NHS, Government and many other organisations as well as Health Service Researchers. HES provides a comprehensive picture of inpatient care that can support public health analysis, research, planning and resource allocation, benchmarking, clinical audit, monitoring and performance management. It can offer a longitudinal picture of particular conditions or procedures. It can support local NHS analysis of activity and allows comparisons between Trusts, PCTs, SHAs, LAs, etc. In addition it also provides data for the construction of a large percentage of the NHS Performance Indicators which summarise quality and performance in the NHS.
History
HES came about in 1987 following a report on the collection and use of hospital activity information published by a steering group chaired by Dame Edith Körner. Before 1987, only a 10 per cent sample of admitted patient records were collected nationally but HES aims to collect a detailed record for each 'episode' of admitted patient care delivered by NHS hospitals in England.
Changes To HES Over Time
Since 1989, the mechanisms for collecting the data have changed considerably, often in response to changes in the organisation of the NHS. For example, HES was initially collated sub-nationally by regional health authorities. In 1996 these bodies were abolished and a national clearing service (the NWCS) was set up to provide a means of transmitting the records. In 2006 the national clearing service was replaced by the Secondary Users Service.
The dataset itself has been modified over time to reflect changing administrative requirements and the introduction of new clinical classifications. In 1995 the recording of diagnoses changed from the 9th to the 10th revision of the International Classification of Diseases (ICD), and in 1997 items were added to carry details of augmented (e.g. intensive) care.
Timeliness Of HES
HES is not a live system and there is a time lag (usually 9-12 months) between the end of the financial year and the availability of data through HES online or as part of the Safe Haven extract, to allow time for data quality checks and validations . Provisional quarterly data are available with a time lag of approximately 3 months. It should also be noted that the HES database is dynamic and may be updated at any time.