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National Statistics

Summary Hospital-level Mortality Indicator (SHMI) - Deaths associated with hospitalisation, England, March 2018 - February 2019

This is part of

National statistics, Official statistics, Open data, Experimental statistics
Publication date:
Geographic coverage:
Geographical granularity:
NHS Trusts, Hospital Sites
Date range:
01 Mar 2018 to 28 Feb 2019


This publication of the SHMI relates to discharges in the reporting period March 2018 - February 2019.

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.

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 one 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).

Key facts

For the 130 trusts included in the SHMI from 1 March 2018 to 28 February 2019:

• There were approximately 9.2 million discharges, from which 288,000 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.  

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

• 15 trusts had a lower than expected number of deaths. 

• Trusts in the same category in the same period in the previous year cannot be highlighted because SHMI values for the same period in the previous year are not available. This is due to the SHMI now being published monthly rather than quarterly. 


1. A large proportion of records for East Sussex Healthcare NHS Trust (trust code RXC) have missing information for the condition the patient was in hospital for and other conditions the patient 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.

2. There have been some methodological changes to the SHMI from the May 2019 publication onwards, including changes to the diagnosis groups used in the calculation of the indicator, the inclusion of an adjustment for seasonality and the inclusion of an adjustment for birthweight in the statistical models for the perinatal diagnosis groups (groups 115-119 and 141). Further information is available in the statement of methodological changes (see Related Links).  

3. 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.

4. An annual report has previously been published as part of the release covering April to March.  The number of users downloading this has become very small and the majority of the content is now available in other parts of the publication, such as the interactive data visualisation.  Therefore, the annual report will no longer be produced.  If users require any of the analysis previously included in the annual report that is not available elsewhere, this can be requested by contacting


Related links

Last edited: 11 November 2019 11:13 am