Patients in NHS hospitals in England are 45% more likely to die in hospital than patients in the USA, according to figures compiled by an eminent doctor and statistician.
Professor Sir Brian Jarman - who invented the hospital standardised mortality rate (HSMR) measure which helped identify under-performance in hospital trusts including Mid-Staffordshire - tracked hospital death rates in seven countries over more than a decade.
He found that in 2004, England was the worst out of the seven, with 22.5% higher death rates than the average and 58% higher than the best performer - the US.
Prof Jarman told Channel 4 News's Cradle to Grave NHS Special that all of the countries have since improved - the UK faster than some. But the 2012 figures show patients are still 45% more likely to die in an English NHS hospital than in America.
For some the conditions which account for large numbers of patient hospital deaths and which affect the elderly in particular, England performed particularly poorly, he said. In 2010, a patient was five times as likely to die of pneumonia and twice as likely to die of septicaemia as a similar patient in the US.
Prof Jarman told C4N: "What I found was the adjusted death rate in England was about 22% higher than the average of all the seven countries that I looked at. It was about 58% higher than the best. I expected us to do well and I was very surprised by the results I got. But there's no means of denying the results. They are absolutely clear.
"I think it gives a very hard measure of differences of adjusted death rates between the different countries. I think we should take notice of it and say 'Is there a problem in the provision of healthcare in England?'"
Prof Jarman said he found the figures "shocking", adding: "When I saw this data, it was probably the stimulus for me to speak more openly about my concerns about the NHS. It's not to say that we don't have some very good hospitals, but I think we also have some very poor hospitals.
"I hope there will be a complete opening up to allow whistle-blowers to say freely the problems that they see, to allow clinicians and patients to be involved in the running of hospitals, to listen to patients. If you go to the States, doctors can talk about problems, nurses can raise problems, they listen to patient complaints. We have a system whereby, at the moment, for written hospital complaints only one in 375 is actually formally investigated. This is absolutely appalling."
The medical director of the NHS, Sir Bruce Keogh, said he would look at the figures to see whether they could be used to improve performance.