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National Statistics
Publication, Part of

Summary Hospital-level Mortality Indicator (SHMI) - Deaths associated with hospitalisation, England, February 2020 - January 2021

National statistics, Official statistics, Open data, Experimental statistics
Publication Date:
Geographic Coverage:
Geographical Granularity:
NHS Trusts, Hospital Sites
Date Range:
01 Feb 2020 to 31 Jan 2021


This publication of the SHMI relates to discharges in the reporting period February 2020 - January 2021.

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 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 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.

Key Facts

For the 123 trusts included in the SHMI from 1 February 2020 to 31 January 2021:

• There were approximately 7.4 million discharges, from which 235,000 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. 

• 12 trusts had a higher than expected number of deaths.  Of these 12 trusts, 4 also had a higher than expected number of deaths for the same period in the previous year.

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

• 13 trusts had a lower than expected number of deaths.  Of these 13 trusts, 11 also had a lower than expected number of deaths for the same period in the previous year.

Image for infographic Interactive data visualisation
Interactive data visualisation


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 has been a fall in the number of spells for most trusts due to COVID-19 impacting on activity from March 2020 onwards and this appears to be an accurate reflection of hospital activity rather than a case of missing data. Further information is available in the contextual indicator ‘Provider spells compared to the pre-pandemic period’ which is part of this publication.

3. The data for St Helens and Knowsley Teaching Hospitals NHS Trust (trust code RBN) has incomplete information on secondary conditions that the patients suffers from, and this will have affected the calculation of the expected number of deaths.  Values for this trust should therefore be interpreted with caution. 

4. Day cases and regular day attenders are excluded from the SHMI.  However, some day cases for University College London Hospitals NHS Foundation Trust (trust code RRV) have been incorrectly classified as ordinary admissions meaning that they have been included in the SHMI. Maidstone and Tunbridge Wells NHS Trust (trust code RWF) has submitted a number of records with a patient classification of ‘day case’ or ‘regular day attender’ and an intended management value of ‘patient to stay in hospital for at least one night’. This mismatch has resulted in the patient classification being updated to ‘ordinary admission’ by the HES data cleaning rules.  This may have resulted in the number of ordinary admissions being overstated. The trust has been contacted to clarify what the correct patient classification is for these records. Values for these trusts should therefore be interpreted with caution. 

5. There is a shortfall in the number of records for Mid Cheshire Hospitals NHS Foundation Trust (trust code RBT) and The Princess Alexandra Hospital NHS Trust (trust code RQW), meaning that values for these trusts are based on incomplete data and should therefore be interpreted with caution.

6. We recommend that values for Guy’s and St Thomas’ NHS Foundation Trust (trust code RJ1) are interpreted with caution as there is a possible shortfall in the number of records which is currently under investigation.  

7. On 1 April 2021 Western Sussex Hospitals NHS Foundation Trust (trust code RYR) merged with Brighton and Sussex University Hospitals NHS Trust (trust code RXH). The new trust is called University Hospitals Sussex NHS Foundation Trust (trust code RYR). This new organisation structure is reflected from this publication onwards.

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.

Data Sets


Related Links

Last edited: 9 June 2021 12:46 pm