SHMI is a good starting point, but is one in a basket of indicators that can be used to highlight areas for further investigation

The Health and Social Care Information Centre has now released the latest Summary Hospital Mortality Indicator (SHMI) figures. SHMI uses a standard and transparent methodology and is an official statistic. The calculation itself is very straightforward. Like other mortality indicators, it is simply the ratio of the observed number of deaths to the expected number of deaths for a trust.

For the SHMI, the calculation uses observed number of deaths either in-hospital, or within 30 days (inclusive) of discharge from the trust. If the patient is treated by another trust within 30 days of discharge, their death is attributed to the last non-specialist acute trust to treat them.

As with all ratios anything that changes numerator or denominator will change the ratio itself. This means we need to look closely at how each is calculated. Our researchers used the experience and insight gained from 25 years of working with mortality indicators to come up with six factors that will have an impact on either the numerator or denominator. You can find our insight report here.

These six factors are: ambulatory care; diagnosis within the first two episodes of care; end of life care; depth of coding; deprivation and the way hospitals code and treat acute myocardial infarction and other conditions.

Some relevant questions you may want to ask include: have we recently changed the recording of any activity or even moved to higher day case rate? Has our Trust’s case mix changed? Is emergency admission flow the same, or are their specialist centres managing conditions like stroke? How do we organise our emergency medical admission services and are we creating more multiple episodes?

There are of course other factors that will be having an impact on an NHS Trust’s SHMI. Some will have a bigger impact on the SHMI than they do on other mortality measures such as RAMI or HSMR.

The key is not to jump to immediate judgement but to call on the best expert advice to find out whether the SHMI has indeed highlighted an area for investigation, or whether something else is at play.

Jason Harries, Managing Director, Capita Health Insight
Our analysis contains HES data which is re-used with the permission of The Health & Social Care Information Centre. All rights reserved.The Health and Social Care Information Centre has now released the latest Summary Hospital Mortality Indicator (SHMI) figures. SHMI uses a standard and transparent methodology and is an official statistic. The calculation itself is very straightforward. Like other mortality indicators, it is simply the ratio of the observed number of deaths to the expected number of deaths for a trust.