Six trusts have been identified as having a “persistently” higher than expected mortality rate according to the summary hospital-level mortality indicator.

The SHMI data, published by the Health and Social Care Information Centre, compares the actual number of patients to die following hospitalisation at a particular trust with the number that would be expected to die, based upon average figures across England and the characteristics of the patients treated there. It includes deaths taking place during a hospital stay and those within 30 days of discharge.

The six trusts were identified by the information centre because they had a higher than expected SHMI during both July 2011–June 2012 and July 2012–June 2013.

They are:

  • Mid Cheshire Hospitals Foundation Trust;
  • Colchester Hospital University Foundation Trust;
  • Aintree University Hospitals Foundation Trust;
  • Wye Valley Trust;
  • Blackpool Teaching Hospitals Foundation Trust; and
  • East Lancashire Hospitals Trust.

Both Colchester Hospital University Foundation Trust and East Lancashire Hospitals Trust are in special measures after failings were identified by Sir Bruce Keogh’s review into hospitals with persistently high mortality rates in spring-summer last year.

Twelve trusts had a lower than expected mortality rate.

The information centre said the data needed to be viewed alongside other evidence and should not be seen as a stand-alone verdict on a trust’s performance.

Information centre chair Kingsley Manning said: “The SHMI, combined with other indicators provides a very useful insight, which should prompt trusts to undertake a further, more detailed examination of their services, but should not be seen as a definitive judgement.”

At the end of last year analytics company Dr Foster published its own mortality data based on four measures - the hospital standardised mortality ratio, the summary hospital-level mortality indicator, deaths after surgery and deaths in low risk conditions.

Three trusts appear on both the information centre and Dr Foster’s outlier lists – Aintree, Blackpool and Mid Cheshire.

A spokesman for Aintree said the latest figures indicated the trust’s SHMI had gone down, partly due to a case note review following every death to ensure lessons were learnt.

He added:  “We anticipate the reduction in SHMI will continue, but it is important to remember that our HSMR…suggests better than average performance, as it has for some time.”

Alex Kafetz, who is a mortality data expert and director of ZPB Associates, said trusts often cited another indicator on which they score better, but they could be failing to address problems.

He said: “Nobody thinks these indicators should be used in isolation - you have to follow it up with local investigation - but it’s pretty dangerous to blame it on problems with the data.

“The analogy I use is if you’re buying a house and you have two surveys done. One says you’re going to need a new roof in a year and the other says everything’s fine, you’re going to at least make sure the one that says you need a new roof isn’t true.”