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Data set, Part of

SHMI site change during spell contextual indicator

Date Range:
01 Mar 2019 to 29 Feb 2020
Publication Date:
Next Publication Date:
13 Aug 2020
Geographic Coverage:
Geographical Granularity:
NHS Trusts


This indicator is designed to accompany the SHMI data at site of treatment level.

The SHMI is calculated at the level of the provider spell, which is a continuous period of time spent as a patient within a single trust (provider). A spell may be composed of more than one episode (a single period of care under one consultant). If a patient is moved between hospitals or sites within the same trust, the provider spell continues. Most spells consist of a single episode and so there is no complication when presenting SHMI data at site level because the entire provider spell occurred at a single site. However, spells consisting of multiple episodes may have occurred over multiple sites and only one of these sites can be associated with the spell. This has been chosen to be the site of the first episode in the spell. This may result in hospital deaths being attributed to a site other than the one in which they occurred, with an impact on the SHMI values presented for the sites concerned. This impact is likely to be greater for sites within trusts showing higher percentages for this contextual indicator.

This new indicator is being published as an experimental statistic. Experimental statistics are official statistics which are published in order to involve users and stakeholders in their development and as a means to build in quality at an early stage.


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 a new contextual indicator 'Percentage of provider spells with COVID-19 coding' which is part of this publication.

2. There is a shortfall in the number of records for Tameside and Glossop Integrated Care NHS Foundation Trust (trust code RMP) and University Hospital Southampton NHS Foundation Trust (trust code RHM). Values for these trusts are based on incomplete data and should therefore be interpreted with caution.

3. Day cases 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.  Values for this trust should therefore be interpreted with caution.

4. The following mergers took place on 1st April 2020: Taunton and Somerset NHS Foundation Trust (trust code RBA) merged with Somerset Partnership NHS Foundation Trust (trust code RH5). The new trust is called Somerset NHS Foundation Trust (trust code RH5). Luton and Dunstable University Hospital NHS Foundation Trust (trust code RC9) merged with Bedford Hospital NHS Trust (trust code RC1). The new trust is called Bedfordshire Hospitals NHS Foundation Trust (trust code RC9). Weston Area Health NHS Trust (trust code RA3) merged with University Hospitals Bristol NHS Foundation Trust (trust code RA7). The new trust is called University Hospitals Bristol and Weston NHS Foundation Trust (trust code RA7). Mid Essex Hospital Services NHS Trust (trust code RQ8) merged with Southend University Hospital NHS Foundation Trust (trust code RAJ) and Basildon and Thurrock University Hospitals NHS Foundation Trust (trust code RDD). The new trust is called Mid and South Essex NHS Foundation Trust (trust code RAJ). Please note that separate indicator values have been produced for these organisations for this publication. From the August 2020 publication onwards, we will reflect these new organisation structures.

5. Further information on data quality can be found in the SHMI background quality report, which can be downloaded from the 'Resources' section of the publication page.