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About the Summary Hospital-level Mortality Indicator (SHMI)
The Summary Hospital-level Mortality Indicator (SHMI) reports on mortality at trust level across the NHS in England using a standard and transparent methodology. It is produced and published monthly as a National Statistic by NHS Digital.
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.
There is an ongoing review of the SHMI to evaluate potential short and long term changes to improve the indicator. User feedback is invaluable to this process and we welcome comments on the proposals going forward. For the latest developments, please refer to the resources within the SHMI research and development section of this page.
COVID-19 activity in the SHMI
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.
If any of the episodes within a provider spell have a COVID-19 diagnosis code, then the spell is excluded from the SHMI.
Additionally, for deaths included in the SHMI, if COVID-19 is recorded anywhere on the death certificate, then the death and the spell it is linked to are excluded from the SHMI. This second exclusion is necessary as the SHMI also includes deaths which occurred outside of hospital within 30 days of discharge.
Activity that is being coded as COVID-19, and therefore excluded, is monitored in a new contextual indicator 'Percentage of provider spells with COVID-19 coding'.
Further information about the exclusion can be found by following the ‘SHMI methodological changes’ link in the ‘Resources’ section below.
Please note that there was a very small amount of COVID-19 activity in the May 2020 and June 2020 SHMI publications but this did not have a significant impact on the data.
Guidance for users
The SHMI's specification is founded on an open and transparent methodology. We expect that the SHMI will need to be interpreted, understood and also reproduced by different users. Therefore, we have provided detailed specification documents on the construction of the SHMI and accompanying contextual indicators.
The mapping from ICD-10 diagnosis codes to SHMI diagnosis groups which is referenced in the specification is also available, along with further information on the construction of the provider spells dataset which is used in the calculation of the indicator.
SHMI Extract Service for trusts
The SHMI Extract Service provides trusts with an extract of the record-level data which have been used to calculate their SHMI. Trusts who have registered for this free service have found that receiving the record-level data and accompanying Variable Life-Adjusted Display Charts (VLADs) is very useful, allowing them to better understand their SHMI and to carry out further analysis and investigations into it. Trusts are only provided with data relating to their trust. Further information and an application form are available below.
SHMI research and development
Reports and further analyses carried out by NHS Digital on the SHMI are published on the SHMI research and development page, along with a methodology development log which contains comments raised on the SHMI methodology and NHS Digital's response to these.
The SHMI is subject to continuous evaluation and the methodology is now due for review. For the latest developments in the SHMI review please refer to the updates in the resources below.
Following the recommendations from the national review of the Hospital Standardised Mortality Ratio (HSMR), the Department of Health and Social Care commissioned NHS Digital to produce and publish the SHMI. As part of the review, the Department of Health and Social Care also commissioned independent statistical modelling work, which was carried out by the School of Health and Related Research (ScHARR) at the University of Sheffield and their report is available to download below.
The SHMI Technical Working Group supported and contributed to the technical work associated with the initial development and construction of the SHMI. Proceedings of the SHMI Technical Working Group are also available on the SHMI research and development page.
We welcome further comments on the SHMI, and suggestions for improvement can be sent to firstname.lastname@example.org.