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Publication, Part of

Summary Hospital-level Mortality Indicator (SHMI) - Deaths associated with hospitalisation, England, September 2021 - August 2022

Accredited official statistics, Official statistics, Open data, Official statistics in development

Publication Date:
12 Jan 2023
Geographic Coverage:
England
Geographical Granularity:
NHS Trusts, Hospital Sites
Date Range:
01 Sep 2021 to 31 Aug 2022
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Page contents

Summary

This publication of the SHMI relates to discharges in the reporting period September 2021 - August 2022.

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.

Highlights

For the 121 trusts included in the SHMI from 1 September 2021 - 31 August 2022:

• There were approximately 8.1 million discharges, from which 248,000 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, 4 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

bit.ly/shmi-vis-sep21aug22

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Notes:

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 Ashford and St Peter's Hospitals NHS Foundation Trust (trust code RTK), County Durham and Darlington NHS Foundation Trust (trust code RXP), Frimley Health NHS Foundation Trust (trust code RDU), Mid Cheshire Hospitals NHS Foundation Trust (trust code RBT), Royal Surrey County Hospital NHS Foundation Trust (trust code RA2), and Wrightington, Wigan and Leigh NHS Foundation Trust (trust code RRF). Values for these trusts are based on incomplete data and should therefore be interpreted with caution.
 
4. There are a high percentage of invalid diagnosis codes for Wye Valley NHS Trust (trust code RLQ). Values for this trust should therefore be interpreted with caution.
 
5. A number of trusts are currently engaging in a pilot to submit Same Day Emergency Care (SDEC) data to the Emergency Care Data Set (ECDS), rather than the Admitted Patient Care (APC) dataset. As the SHMI is calculated using APC data, this does have the potential to impact on the SHMI value for these trusts. Trusts with SDEC activity removed from the APC data have generally seen an increase in the SHMI value. This is because the observed number of deaths remains approximately the same as the mortality rate for this cohort is very low; secondly, the expected number of deaths decreases because a large number of spells are removed, all of which would have had a small, non-zero risk of mortality contributing to the expected number of deaths. NHS Digital are working with NHS England to better understand the planned changes to the recording of SDEC activity and the potential impact on the SHMI. The trusts affected in this publication are: 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), Norfolk and Norwich University Hospitals NHS Foundation Trust (trust code RM1), and University Hospitals of Derby and Burton NHS Foundation Trust (trust code RTG).

6. 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: 20 January 2023 2:51 pm