By Thomas Moore, Health and Science Correspondent
Thousands of patient deaths are to be investigated to see whether they could have been avoided in a new drive to make the NHS safer.
For the first time anywhere in the world the medical notes of around 2,000 patients who have died in England will be analysed by experts every year.
The data will be used to give the most comprehensive ever estimate of avoidable mortality in hospitals around the country.
Every hospital chairman will have to write to the Health Secretary annually setting out their plan for eradicating unnecessary deaths.
Jeremy Hunt said: "I'm determined to go even further in rooting out poor care.
"I want all hospital boards to have a laser-like focus on eradicating avoidable deaths in their organisation; even one life lost to poor care or safety error is too many."
The announcement comes as a new analysis revealed that 11 hospital trusts put under 'special measures' 18 months ago because of their high death rates have dramatically improved their care.
Extra staff, management changes and mentoring by more successful NHS organisations cut death rates at the 11 hospitals by more than 9% - three times more than the national average.
Health analysis company Dr Foster, which carried out the research, estimated that at least 450 lives have been saved as a result.
Roger Taylor, who led the research, said: "We were not expecting to find such a strong result.
"It is remarkable to see this intervention has produced a real change and improvement for patients.
"It has saved lives and produced better care."
A further eight hospital trusts have since been put into special measures, bringing the total to 19.
The Department of Health said the trusts have employed an extra 1,800 nurses and 110 doctors. Almost 130 senior managers have been replaced.
Mr Hunt will this week publish a report on the culture change in the NHS in the two years since the inquiry into the Mid-Staffs hospital scandal.
He is expected to announce new measures to support staff to speak up about poor or unsafe care.
Shadow health minister Andrew Gwynne says the review is not ambitious enough.
He added: "Labour is looking at whether we can go further and have a mandatory review of case notes for every death in hospital - not just for a sample of cases as Jeremy Hunt proposes.
"But as well as initiatives to measure avoidable harm, we need action to prevent it from happening in the first place. The sad truth is that by turning the NHS upside down with a damaging reorganisation and causing a crisis in A&E, the Tory-led Government is making care problems more likely, not less."
