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Publication, Part of

Summary Hospital-level Mortality Indicator (SHMI) - Deaths associated with hospitalisation, England, November 2022 - October 2023

National statistics, Official statistics, Open data, Experimental statistics

National Statistics


This publication of the SHMI relates to discharges in the reporting period November 2022 - October 2023

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. The SHMI covers patients admitted to hospitals in England who died either while in hospital or within 30 days of being discharged. Deaths related to COVID-19 are excluded from the SHMI.

To help users of the data understand the SHMI, trusts have been categorised into bandings indicating whether a trust's SHMI is 'higher than expected', 'as expected' or 'lower than expected'. For any given number of expected deaths, a range of observed deaths is considered to be 'as expected'. If the observed number of deaths falls outside of this range, the trust in question is considered to have a higher or lower SHMI than expected. The expected number of deaths is a statistical construct and is not a count of patients. The difference between the number of observed deaths and the number of expected deaths cannot be interpreted as the number of avoidable deaths or excess deaths for the trust.

The SHMI is not a measure of quality of care. A higher than expected number of deaths should not immediately be interpreted as indicating poor performance and instead should be viewed as a 'smoke alarm' which requires further investigation. Similarly, an 'as expected' or 'lower than expected' SHMI should not immediately be interpreted as indicating satisfactory or good performance.

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, as well as a breakdown of the data by diagnosis group.

Further background information and supporting documents, including information on how to interpret the SHMI, are available on the SHMI homepage (see Related Links). Information about the exclusion of COVID-19 from the SHMI can also be found on the same page. A link to the methodological changes statement which details the exclusion is also available in the Related Links section

For the 119 trusts included in the SHMI from 1 November 2022 to 31 October 2023:

• There were approximately 8.7 million discharges, from which 266,000 deaths were recorded either while in hospital or within 30 days of discharge. This includes deaths from other causes as well as deaths related to the reason for the hospital admission. 

• 11 trusts had a higher than expected number of deaths.  Of these 11 trusts, 6 also had a higher than expected number of deaths for the same period in the previous year.

• 96 trusts had a number of deaths within the expected range.  

• 12 trusts had a lower than expected number of deaths.  Of these 12 trusts, 9 also had a lower than expected number of deaths for the same period in the previous year.

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1. As of the July 2020 publication, COVID-19 activity has been excluded from the SHMI. The SHMI is not designed for this type of pandemic activity and the statistical modelling used to calculate the SHMI may not be as robust if such activity were included. Activity that is being coded as COVID-19, and therefore excluded, is monitored in the contextual indicator 'Percentage of provider spells with COVID-19 coding' which is part of this publication.

2. Please note that there was a fall in the overall number of spells from March 2020 due to COVID-19 impacting on activity for England and the number has not returned to pre-pandemic levels. Further information at Trust level is available in the contextual indicator ‘Provider spells compared to the pre-pandemic period’ which is part of this publication.

3. There is a shortfall in the number of records for The Princess Alexandra Hospital NHS Trust (trust code RQW), Guy’s and St Thomas’ NHS Foundation Trust (RJ1), King’s College Hospital NHS Foundation Trust (RJZ), and East Lancashire Hospitals NHS Trust (RXR). Values for these trusts are based on incomplete data and should therefore be interpreted with caution.

4. Frimley Health NHS Foundation Trust (trust code RDU) stopped submitting data to the Secondary Uses Service (SUS) during June 2022 and did not start submitting data again until April 2023 due to an issue with their patient records system. This is causing a large shortfall in records and values for this trust should be viewed in the context of this issue.

5. There is a high percentage of invalid diagnosis codes for Chesterfield Royal Hospital NHS Foundation Trust (trust code RFS), Milton Keynes University Hospital NHS Foundation Trust (trust code RD8), West Suffolk NHS Foundation Trust (trust code RGR), and Portsmouth Hospitals University NHS Trust (RHU). 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.

Last edited: 13 March 2024 4:00 pm