The SHMI is the ratio between the actual number of patients who die following hospitalisation at the trust and the number that would be expected to die on the basis of average England figures, given the characteristics of the patients treated there. It includes deaths which occurred in hospital and deaths which occurred outside of hospital within 30 days (inclusive) of discharge.
The SHMI gives an indication for each non-specialist acute NHS trust in England whether the observed number of deaths within 30 days of discharge from hospital was 'higher than expected' (SHMI banding=1), 'as expected' (SHMI banding=2) or 'lower than expected' (SHMI banding=3) when compared to the national baseline.
Trusts may be located at multiple sites and may be responsible for 1 or more hospitals. A breakdown of the data by site of treatment is also provided.
The SHMI is composed of 144 different diagnosis groups and these are aggregated to calculate the overall SHMI value for each trust. The number of finished provider spells, observed deaths and expected deaths at diagnosis group level for each trust is available in the SHMI diagnosis group breakdown files. For a subset of diagnosis groups, an indication of whether the observed number of deaths within 30 days of discharge from hospital was 'higher than expected', 'as expected' or 'lower than expected' when compared to the national baseline is also provided.
Details of the 144 diagnosis groups can be found in Appendix A of the SHMI specification.
Notes:
1. For discharges in the reporting period April 2024 - May 2024, most of the records for Wirral University Teaching Hospital NHS Foundation Trust (trust code RBL) have been submitted without an NHS number. This will have affected the linkage of the HES data to the ONS death registrations data and may have resulted in a smaller number of deaths occurring outside hospital within 30 days of discharge being identified for this trust than would have otherwise been the case. The results for this trust should therefore be interpreted with caution.
2. Northern Lincolnshire and Goole NHS Foundation Trust (trust code RJL) has a high percentage of records with no NHS Number. This is resulting in around 40% of their spells not having a value for Age or Deprivation rank. As Age is a component of the statistical models used to calculate the SHMI, values for this trust should therefore be interpreted with caution.
3. There is a shortfall in the number of records for North Middlesex University Hospital NHS Trust (trust code RAP), Northumbria Healthcare NHS Foundation Trust (trust code RTF), The Rotherham NHS Foundation Trust (trust code RFR), and The Shrewsbury and Telford Hospital NHS Trust (trust code RXW). Values for these trusts are based on incomplete data and should therefore be interpreted with caution.
4. There is a high percentage of records with missing data for the Sex field for Guy’s and St Thomas’ NHS Foundation Trust (trust code RJ1) and University Hospitals Dorset NHS Foundation Trust (trust code R0D). Values for these trusts should therefore be interpreted with caution.
5. There is a high percentage of invalid diagnosis codes for Bradford Teaching Hospitals NHS Foundation Trust (trust code RAE), Chesterfield Royal Hospital NHS Foundation Trust (trust code RFS), East Lancashire Hospitals NHS Trust (trust code RXR), Harrogate and District NHS Foundation Trust (trust code RCD), Portsmouth Hospitals University NHS Trust (trust code RHU), University Hospitals of North Midlands NHS Trust (trust code RJE), and University Hospitals Plymouth NHS Trust (trust code RK9). Values for these trusts should therefore be interpreted with caution.
6. A number of trusts are now submitting Same Day Emergency Care (SDEC) data to the Emergency Care Data Set (ECDS) rather than the Admitted Patient Care (APC) dataset. The SHMI is calculated using APC data. Removal of SDEC activity from the APC data may impact a trust’s SHMI value and may increase it. More information about this is available in the Background Quality Report.
7. 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.