NHS trusts have been waiting with trepidation to hear their performance ratings from the new health service regulator, the Care Quality Commission.
The findings on quality of services and financial management will help to make or break the reputations of hospitals, primary care trusts, ambulance services and other health organisations across England.
But some patients groups say the ratings rely too heavily on self assessment by trust managers.
They believe the regulator's conclusions cannot be trusted.
These fears were raised following the scandal at the Mid Staffordshire NHS trust.
A special investigation by the Healthcare Commission, published earlier this year, revealed that patients had been assessed by receptionists with no clinical training.
There were shortages of doctors and nurses, poor training, and a lack of equipment.
The report concluded that there had been a failure of leadership.
Yet the trust's provisional rating awarded by the Healthcare Commission six months earlier was "good".
It was the trust's death rates - first spotted by the health researchers Doctor Foster - that prompted a formal inquiry.
No one had acted on complaints from patients families.
Julie Bayley, who set up their campaign group Cure the NHS, said despite promises of action, many of the problems are still there.
She does not believe the Care Quality Commission will be able to sort things out.
"We just have no confidence in this regulatory body," she said.
"This is why we wanted a public inquiry, so that these regulatory bodies would say what went wrong.
"Why didn't they spot what was going on at Stafford hospital?"
The Patients Association has reported other examples of appalling care across the health service.
It says the proportion of patients affected is small, but still amounts to thousands of people.
The association's vice chairman, Michael Summers, wants to see much tighter scrutiny by the regulator, based on more inspections.
"We have to get away from reliance upon self-assessment," he said.
"That is often misleading. We really want to have onsite inspections, seeing hospitals in the raw as they operate on a daily basis.
"We need to see how clinical areas are being dealt with, see about staff ratios and the like.
"That's the best way to make an assessment of whether a hospital is operating adequately or not."
Nigel Edwards, from the NHS Confederation, which speaks for health service trusts, said they have to contend with at least 69 regulatory audit, inspection and accreditation bodies delving around for information.
He is concerned that too much regulation could create a false assurance that everything is OK, when in reality it is the responsibility of the board to ensure high standards.
He said sending in more inspectors would not necessarily produce more reliable information.
"If you go in and inspect then people will prepare to pass the test that you've set them," he said.
"If you rely on self-reporting and self-certification there is a danger of complacency and really not recognising what good looks like.
"And somewhere between those two what we're hoping for is regulation as an ultimate backstop to ensure that at the very least minimum standards are met and continue to improve."
The new chief executive at Mid Staffordshire, Antony Sumara, said health service managers - and the regulator - have learned important lessons from the scandal.
"I think there is maybe a mid-Staffs effect, that this hospital did have a history of pressing all the buttons as far as assessment was concerned, and look what happened," he said.
"But my sense is that the self-assessment process is much more rigourous, more questions are asked, more visits are done.
"So actually there's much more of a sense out there of is this true or not?"
He is now working with patients groups to try to restore confidence in the trust -- which has again been rated as weak.
He acknowledges it will not be easy, but the care quality commission will also have to demonstrate that it can effectively protect and promote the interests of patients - particularly at a time when trusts are coming under growing pressure to cut their costs.
The commission said there has never been a more comprehensive assessment of the NHS.
It said it has included hundreds of thousands of pieces of information, including declarations from all trust boards together with about eight thousand comments from representatives of patients.
It said one in five trusts have been inspected on core standards.
A spokesman for the Department of Health in England said: "Since the events at Mid-Staffs took place, firm action has been taken locally and nationally, reflecting the collective commitment at all levels in the system to prevent the problem being repeated."