Death rates at 19 hospital trusts in England were alarmingly high last year, according to the latest Dr Foster Hospital Guide.

The annual guide also identified four trusts where an unexpectedly high number of patients died after surgery, including Hull and East Yorkshire Hospitals Trust, where there were 33 more deaths than expected.

Dr Foster said the mortality rates should act as a warning sign of potential problems in the quality of care.

Health secretary Andrew Lansley welcomed the report, saying: “I have been clear that unsafe care will not be tolerated. Patients have a right to expect the very best care from the NHS and when something goes wrong, hospitals have a duty to report it and make sure that others can learn from their mistake.

“We have already taken action to improve safety and openness in the NHS - publishing more information and statistics for all to see, extending the list of mistakes the NHS will not be paid for and strengthening rights for whistleblowers.”

The Dr Foster report revealed 30,500 patients developed a blood clot, more than 13,000 mothers suffered an obstetric tear while giving birth, almost 10,000 patients suffered an accidental puncture or laceration, more than 2,000 had post-operative intestinal bleeding and 1,300 patients contracted blood poisoning after surgery.

Nigel Edwards, acting chief executive of the NHS Confederation, said: “The concerns Dr Foster raises over the way information is recorded and interpreted in the health service are very important.

“If we are going to manage and measure our health service using data on the outcomes of procedures and the success of treatments then we need to ensure that the collection of usable data is a priority and embedded in the culture of the health service.”

The number of England’s 147 trusts reported to have high hospital standardised mortality rates (HSMRs), fell from 27 to 19, with the gaps between hospitals with the highest and lowest rates narrowing.

In other good news, the number of people dying in hospital fell by 7 per cent between 2008-09 and 2009-10 and the reporting of errors seems to have improved.

Of the 19 trusts with high HSMRs, Royal Bolton Hospital and Pennine Acute Hospitals have been high for six years.

While University College London Hospitals and Royal Free Hampstead had 28 per cent lower than expected mortality ratios, Buckinghamshire Hospitals was 18 per cent higher than expected.

Newcastle upon Tyne Hospitals, University Hospital of North Staffordshire, University Hospitals Birmingham (UHB) and Hull and East Yorkshire, had significantly high “death after surgery” rates, with the later two trusts suffering both high rates of both HSMRs and deaths after surgery.

As reported by HSJ, Dr Dave Rosser, executive medical director of University Hospitals Birmingham Foundation Trust, launched a pre emptive defence of his trust before the publication of the guide in Sunday’s Observer newspaper.

He said: “The figures do not accurately reflect the quality of care given at the Queen Elizabeth Hospital Birmingham.

“We believe there is a risk that figures like these could cause unnecessary confusion and distress amongst patients and are a distraction to concentrating on providing the best in care for our patients.”

He described the methodology as “fundamentally flawed and misleading” as well as “destructive and unhelpful” and said the figures may have been skewed by the high number of patients with liver disease.

He continued: “The Care Quality Commission, which regulates clinical standards across NHS hospitals, is also satisfied that there are no causes for concern regarding our mortality rates or deaths after surgery.”