Summary Hospital-level Mortality Indicator (SHMI) - Deaths associated with hospitalisation, England, Experimental Statistics

Summary This is the first publication of the Summary Hospital-level Mortality Indicator (SHMI). The SHMI is a ratio of the observed deaths in a trust over a period of time divided by the expected number given the characteristics of patients treated by that trust. When it's published The SHMI is produced and published quarterly by the NHS IC. Production and publication of the SHMI follows the Code of Practice for Official Statistics. The SHMI is being published as ‘Experimental Statistics' which are new Official Statistics that are under going review. Like all indicators managed by the NHS IC, the SHMI will be subject to continuous review, using the Indicator Assurance Process. Outputs from these reviews will be reported to the National Quality Board, and will be available on the NHS IC's website. How it's calculated The data used to calculate the SHMI is generated from data that Trusts have submitted to SUS (Secondary Uses Services). This data is then processed by the NHS IC to create HES data (Hospital Episode Statistics). Data from the Office for National Statistics (ONS) death registrations is linked to this HES data in order to capture deaths which occur outside hospitals. It is this linked dataset which is used to construct the SHMI. We expect that the SHMI will need to be interpreted, understood and also reproduced, if necessary, by interested parties. Therefore, the NHS IC has published the specification that details the construction of the SHMI along with related methodological information and details of the development process. How to use the SHMI The SHMI requires careful interpretation, and should not be taken in isolation as a headline figure of trust performance. It is best treated as a ‘smoke alarm'. The SHMI is an indication of whether individual trusts are conforming to the national baseline of hospital-related mortality. Mortality within a trust is described as either ‘as expected', ‘lower than expected' or ‘higher than expected'. Trusts whose SHMI value is ‘higher than expected' should follow-up – investigate to identify any underlying causes why this may be and action changes as appropriate. In addition, lessons could be learnt across the NHS from those trusts whose SHMI value is ‘lower than expected'. The SHMI value for each trust is plotted against the trust's expected number of deaths on ‘funnel plots'. If the observed number of deaths falls outside of an expected range the Trust in question will be considered to have a higher or lower SHMI than expected. The range, the extremes of which are called control limits, can be calculated in a variety of ways and are shown on the funnel plots. For the SHMI two options are presented: exact Poisson control limits at a 99.8% level and over dispersion control limits at a 95% level. Who can use SHMI The SHMI can be used locally by individual hospital trusts to assess and investigate their mortality related outcomes. Regulators and commissioning organisations can also use the SHMI to investigate outcomes for Trusts under their jurisdiction. In all of these cases the SHMI should not be used in isolation but in conjunction with other indicators and information from other sources (patient feedback, staff surveys and other such material) that together form a holistic view of Trust outcomes and a fuller overview of how Trust processes are impacting on outcomes. While the public and patients will be interested in the SHMI, is not intended primarily for use by patients or the public. Although this information is in the public domain it has not been specifically tailored to be easily accessible for a patient or public audience. Key facts: In the period from 1 April 2010 to 31 March 2011, there were ■14 trusts whose SHMI value was ‘higher than expected' under both methods and; ■14 trusts whose SHMI value was ‘lower than expected' under both methods