This indicator is designed to accompany the SHMI data at site of treatment level.
The SHMI is calculated at the level of the provider spell, which is a continuous period of time spent as a patient within a single trust (provider). A spell may be composed of more than 1 episode (a single period of care under 1 consultant). If a patient is moved between hospitals or sites within the same trust, the provider spell continues. Most spells consist of a single episode and so there is no complication when presenting SHMI data at site level because the entire provider spell occurred at a single site.
However, spells consisting of multiple episodes may have occurred over multiple sites and only 1 of these sites can be associated with the spell. This has been chosen to be the site of the 1st episode in the spell. This may result in hospital deaths being attributed to a site other than the one in which they occurred, with an impact on the SHMI values presented for the sites concerned. This impact is likely to be greater for sites within trusts showing higher percentages for this contextual indicator.
Notes:
1. There is a shortfall in the number of records for Buckinghamshire Healthcare NHS Trust (trust code RXQ), Mid Cheshire Hospitals NHS Foundation Trust (trust code RBT) and Torbay and South Devon NHS Foundation Trust (trust code RA9). Values for these trusts are based on incomplete data and should therefore be interpreted with caution.
2. Due to a problem with the process which links Hospital Episode Statistics (HES) data to the Office for National Statistics (ONS) death registrations data, some in-hospital deaths have been counted as survivals in a small number of trusts. This affects 126 spells in the May 2025 to April 2026 time period for Wirral University Teaching Hospital NHS Foundation Trust (trust code RBL) meaning that the number of observed deaths has been underestimated and so the results for this trust should be interpreted with caution. For the other trusts, the number of affected spells (and hence the impact on the SHMI) is small.
3. On 1st July 2026, North Bristol NHS Trust (trust code RVJ) was acquired by University Hospitals Bristol and Weston NHS Foundation Trust (trust code RA7). The new organisation is called Bristol NHS Foundation Trust (trust code RA7). In this publication, data are still presented for the two separate organisations. Data will be presented for the new trust at a later date.
4. There are variations between trusts in the recording of same day emergency care (SDEC). Where trusts are submitting SDEC activity as part of the Outpatient dataset or Emergency Care Data Set (ECDS) rather than the Admitted Patient Care (APC) dataset or are recording this activity as day cases within the APC data, these records will not be included in the SHMI. Trusts with SDEC activity removed from the SHMI data have seen an increase in their SHMI value. As all trusts are expected to transition to recording SDEC activity as admitted patients, the data will become more comparable over time and the impact on the SHMI will reduce.
5. Further information on data quality can be found in the SHMI background quality report, which can be downloaded from the 'Resources' section of this page.