As many as 3,000 people may have died needlessly in just one year at the 14 hospital trusts that are being investigated by health officials for having higher than expected mortality rates, figures show.
Following the publication of the report into serious failings at Mid-Staffordshire Trust, NHS England medical director Professor Sir Bruce Keogh launched an investigation into the trusts because of their high mortality rates.
Nine of the trusts have been ”outliers” on the Hospital Standardised Mortality Ratio (HSMR) for two years running and the other five were identified by the Summary Hospital-level Mortality Indicator (SHMI) as having higher than expected death rates.
The latest SHMI figures, which compare the number of patients who died following admission to hospital with the number who would be expected to die, show that in just one year there were 2,997 more deaths than would have been expected.
The SHMI, which concerns figures for a year from October 2011, identified 10 trusts as having “higher than expected” death rates - of these, eight are being investigated in the Keogh mortality review.
The other six trusts under review have been classed as having death rates “as expected”, including Burton Hospitals Trust which actually had 15 fewer deaths than predicted.
Blackpool Teaching Hospitals Trust was estimated to have 1,947 deaths but actually had 2,357 - a difference of 410, according to the figures published by the Health and Social Care Information Centre.
The figures also suggest that five of the trusts which are being investigated are “repeat outliers” - having being classed as “higher than expected” for two years running.
Basildon and Thurrock University Hospitals Trust, Colchester Hospital University Trust, Northern Lincolnshire and Goole Hospitals Trust, Tameside Hospital Trust, and the Blackpool trust were categorised as higher than expected from October 2010 to October 2012.
The trusts had a combined total of almost 1,500 more deaths than expected in 2011 to 2012 - according to the figures.
Officials cautioned that the data is “experimental” and the figures should only act as a “smoke alarm”.
Sir Bruce said: “A higher than expected mortality rate does not in itself tell us that a hospital is unsafe, for example, units delivering highly complex and specialist care could legitimately have higher mortality rates.
“It is, however, a warning light that suggests trusts should investigate further to identify and resolve any care quality issues.
“We want consistently high performing hospitals across the NHS.
“Hospitals with persistently high Summary Hospital Mortality Indicator scores are currently under review.”
Mortality data have been much debated in recent weeks following the temporary suspension of the children’s heart surgery unit at Leeds General Infirmary. Figures presented to Sir Bruce suggested that death rates at the unit were double that of other centres.
But medical bodies, doctors and other experts questioned the accuracy of the data used to support the suspension of surgery, which they said was unverified and not fit to base such a decision on.
On Wednesday, health secretary Jeremy Hunt told the Health Select Committee: “(Mortality data) have to be treated with caution because it is excess mortality against a mean, it doesn’t mean that every example of excess mortality is an avoidable death, but it does mean you should investigate and that’s what’s happening.”
NHS England said that the 14 trusts under investigation would soon be visited by a team of experts including doctors, nurses and patient representatives.
A spokeswoman said that the teams will carry out “rapid responsive reviews” and will observe the hospital in action, as well as taking part in meetings with patients, members of the public, and staff. These visits will be followed up with unannounced visits, she added.