Regulation of the Health Service has come under scrutiny after an independent organisation published its own hospital league table.

Health minister Mike O'Brien has defended the work of the Care Quality Commission (CQC), which he said was more reliable than that of Dr Foster, which provides guides to health and social care.

The public-private stats firm published a report yesterday claiming that a dozen hospitals are "significantly underperforming", contradicting the verdict of official regulator CQC, which said that nine of those hospitals were good or excellent.

The CQC regime depends on self-assessments by hospital trusts, which are checked against other statistics and during routine and unannounced on-site inspections.

O'Brien said that while CQC "actually goes in and it inspects any hospitals it has concerns about"; Dr Foster Intelligence "just looks at the statistics and it derives conclusions from the statistics. If you are looking at who do you rely on, it is the Care Quality Commission."

The commission has identified Basildon, one of the hospitals on Dr Foster's underperforming list, as needing help, he said.

CQC chair Baroness Young has also spoken out, claiming that some of the Dr Foster data was "quite alarmist".

"Where they are good we will take them into account in our regulatory work and where they are flaky, we won't," she said, insisting the official watchdog's regime was far more detailed.

A CQC spokesman said comparison of the Dr Foster figures and its own assessments were "spurious" as they measured different things and employed different methodology.

However, the director of the Patients' Association, Katherine Murphy, has accused the government's watchdog of being "toothless".

"What confidence can we have in a system that claims hospitals are excellent or good when in fact they are consistently underperforming?

"The public will be so confused because there is so much conflicting information."