Data collection
In England all NHS hospitals are organised into trusts. Each trust
provides secondary and tertiary care for a geographically defined
catchment population. Typically, each trust runs between one and four
larger district hospitals depending on the size and spread of their
catchment population and local service delivery models. HES data are
collected from all NHS Trusts in England and related to episodes of
hospital care provided by the NHS. The data are entered by trained data
coders within each trust. We used data for the six-year period
1st January 2014 to 31st December
2019.