The HES processing cycle and data quality checks

HES data for admitted patients, outpatients and A&E comes from the routine exchanges of information between providers and commissioners of healthcare for NHS patients in England. It includes private patients treated in NHS hospitals, patients who were resident outside of England and care delivered by treatment centres (including those in the independent sector) funded by the NHS. The Emergency Care Data Set (ECDS) replaced the HES A&E dataset, for activity from April 2020, as the national dataset for urgent and emergency care used to collect information from Emergency Departments across England.

Healthcare providers collect administrative and clinical information locally to support the care of the patient. The data is submitted to the Secondary Uses Service (SUS), which, as well as making it available to the commissioners, also copies the information to a database.

At pre-arranged ‘inclusion’ dates during the year, SUS takes an extract from their database and sends it to HES. Data on SUS will continue to change, but HES data is fixed as it was when that extract was taken. Hence there are likely to be differences between analyses from the SUS and those from HES.

A number of automated cleaning rules are then applied to the data, before deriving new items and making the information available for HES users. Data quality reports and checks are completed at various stages in the cleaning and processing cycle.