Hospital Episode Statistics (HES) is a database containing details of all admissions, A and E attendances and outpatient appointments at NHS hospitals in England.

Initially this data is collected during a patient's time at hospital as part of the Commissioning Data Set (CDS). This is submitted to NHS Digital for processing and is returned to healthcare providers as the Secondary Uses Service (SUS) data set and includes information relating to payment for activity undertaken. It allows hospitals to be paid for the care they deliver.

This same data can also be processed and used for non-clinical purposes, such as research and planning health services. Because these uses are not to do with direct patient care, they are called 'secondary uses'. This is the HES data set.

• HES data covers all NHS Clinical Commissioning Groups (CCGs) in England, 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

We apply a strict statistical disclosure control in accordance with the NHS Digital protocol, to all published HES data. This suppresses small numbers to stop people identifying themselves and others, to ensure that patient confidentiality is maintained. https://digital.nhs.uk/data-and-information/publications/statistical/hospital-accident--emergency-activity