Skip to main content
Creating a new NHS England: Health Education England, NHS Digital and NHS England have merged. More about the merger.

Publication, Part of

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

National statistics, Official statistics, Open data, Experimental statistics

National Statistics


This publication of the SHMI relates to discharges in the reporting period April 2022 - March 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 120 trusts included in the SHMI from 1 April 2022 to 31 March 2023:

• There were approximately 8.3 million discharges, from which 260,000 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. 

• 10 trusts had a higher than expected number of deaths.  Of these 10 trusts, 5 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.  

• 14 trusts had a lower than expected number of deaths.  Of these 14 trusts, 10 also had a lower than expected number of deaths for the same period in the previous year.

Interactive data visualisation

In order to access this visualisation and its functionality, we recommend the following internet browsers:

Microsoft Edge

Chrome desktop latest version

Safari Mac latest version

Firefox desktop latest version 


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 for England from March 2020 due to COVID-19 impacting on activity 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). Values for this trust are based on incomplete data and should therefore be interpreted with caution.

4. Frimley Health NHS Foundation Trust (trust code RDU) has not submitted data to the Secondary Uses Service (SUS) since June 2022 due to an issue with their patient records system. This is causing a large shortfall in records with data only submitted for 3 months out of the 12 months in the current time period. Values for this trust should be viewed in the context of this issue. 

5. There is a high percentage of invalid diagnosis codes for Milton Keynes University Hospital NHS Foundation Trust (trust code RD8). Values for this trust should therefore be interpreted with caution.

6. Barts Health NHS Trust (trust code R1H), Cambridge University Hospitals NHS Foundation Trust (trust code RGT), Croydon Health Services NHS Trust (trust code RJ6), Epsom and St Helier University Hospitals NHS Trust (trust code RVR), Frimley Health NHS Foundation Trust (trust code RDU), Imperial College Healthcare NHS Trust (trust code RYJ), Manchester University NHS Foundation Trust (trust code R0A), Norfolk and Norwich University Hospitals NHS Foundation Trust (trust code RM1), and University Hospitals of Derby and Burton NHS Foundation Trust (trust code RTG)  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 is available in the Background Quality Report. 

7. On 1 July 2023 Southport and Ormskirk Hospital NHS Trust (trust code RVY) was acquired by St Helens and Knowsley Teaching Hospitals NHS Trust (trust code RBN). The new organisation is known as Mersey and West Lancashire Teaching Hospitals NHS Trust (trust code RBN). However, as we received notification of this change after data processing for this publication began, data are still reported for the two separate organisations. NHS England are planning to report data for the new merged organisation from the October 2023 publication.

8. 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: 10 August 2023 9:31 am