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).