Severe nurse shortages have been linked to high death rates at Midland hospitals in a new report by watchdogs.

Dr Foster Intelligence, which compiles vital health data on hospitals nationwide, has revealed the extent to which staffing levels can impact on patient mortality rates.

Figures highlight problems at Mid Staffordshire Foundation Trust, which was shamed in a report this month over at least 400 deaths at Stafford Hospital due to severe cuts to staffing and care to hit financial targets.

But Walsall Hospitals Trust, which runs Manor Hospital, has the lowest rate of nurses in the region and high death rates, with South Warwickshire General Hospitals and George Eliot Hospital, in Nuneaton, also showing poor numbers of nurses per bed.

Dudley Group of Hospitals Foundation Trust, in charge of Russells Hall Hospital, was the second worst in the region for nursing levels but had an average mortality rating.

Dr Peter Carter, chief executive of the Royal College of Nursing, said: “It’s very simple. When hospitals do not have enough nurses, patients are put at risk.”

Researchers analysed staffing levels at 147 hospitals with A&E departments between April 1, 2007, and March 31 last year and found death rates were lower and hospital stays were shorter at hospitals that had more nurses per bed.

They also discovered that of the 49 trusts with the lowest nurse per bed ratios, nearly half were rated as having a high death rate in the hospital standardised mortality ratio.

High death rates were also recorded at Burton Hospitals, Heart of England Foundation Trust, which runs Heartlands, Sutton Coldfield’s Good Hope and Solihull hospitals, University Hospitals Coventry and Warwickshire, Worcestershire Acute Hospitals and University Hospital Birmingham Foundation Trust, in charge of Selly Oak and Edgbaston’s Queen Elizabeth hospitals.

All of these had less than two nurses per bed.

Dr Simon Jones, chief statistician at Dr Foster Intelligence, who led the research, said: “This data shows that nursing levels are an important factor in ensuring a low death rate in hospitals, but it’s important to recognise there are also other reasons.”

Sue James, chief executive for Walsall Manor Hospital, said mortality rates at Manor Hospital had almost halved over the past eight years.

She said: “Staffing levels are agreed for each ward and maintained with the help of an excellent nurse bank and a new computerised rostering system.

“This is the first time we have seen these disparate data being presented together in this way and at face value it is difficult to comment on their validity.

“A recent study carried out by Birmingham University concluded that for the purpose of comparing hospitals, the standard mortality ratio is not a reliable indicator of the quality of care that patients receive, however we do use it as an internal benchmark.”

Helen Moss, director of nursing at Mid Staffordshire Foundation Trust, said: “Since January 2008, we have recruited over 100 additional nurses, including an additional nine matrons.

“Since the data was collected, the trust’s standard hospital mortality rate has reduced to currently lying below the national average.”