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Publication, Part of

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

National statistics, Official statistics, Open data, Experimental statistics

National Statistics


This publication of the SHMI relates to discharges in the reporting period August 2020 - July 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.

For the 122 trusts included in the SHMI from 1 August 2020 to 31 July 2021:

• There were approximately 7.9 million discharges, from which 232,000 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. 

• 14 trusts had a higher than expected number of deaths.  Of these 14 trusts, 8 also had a higher than expected number of deaths for the same period in the previous year.

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

• 14 trusts had a lower than expected number of deaths.  Of these 14 trusts, 11 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 has been a fall in the overall number of spells 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. A large proportion of records for Mid and South Essex NHS Foundation Trust (trust code RAJ) have missing or incorrect information for the main condition the patient was in hospital for (their primary diagnosis) which affects data between April 2020 and March 2021. Due to the impact of this on the underlying SHMI models, all data for this trust has been excluded. Work is ongoing to correct the underlying data for this trust and once complete it will be included in future publications.

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 Hospital Episode Statistics (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. On 1 October 2021 Pennine Acute Hospitals NHS Trust (trust code RW6) merged with Salford Royal NHS Foundation Trust (trust code RM3). The new trust is called Northern Care Alliance NHS Foundation Trust (trust code RM3). However, as we received notification of this change after data processing for this publication began, separate indicator values have been produced for this publication. This will be updated in future publications to reflect the new organisation structure.

6.  There is a shortfall in the number of records for Countess of Chester Hospital NHS Foundation Trust (trust code RJR) meaning that values for this trust are based on incomplete data and should therefore be interpreted with caution.

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: 8 December 2021 12:57 pm