The Dr Foster Hospital Guide 2009 has named 12 NHS trusts that it says have significantly underperformed on its new measure of patient safety.

The guide, published over the weekend, identifies patient safety as the single most important element of hospital care.

For the first time, it has introduced a Patient Safety Score, awarding scores of one to the poorest performers and five to the best.

The exercise is proving controversial as it follows revelations last week about poor standards of care at Basildon and Thurrock University NHS Foundation Trust. The trust received a “good” rating from the Care Quality Commission but clocked up a zero rating on Dr Foster’s Patient Safety Score.

Health secretary Andy Burnham stepped in over the weekend to ask the CQC to establish whether any NHS trusts have similar issues to those raised about Basildon.

The CQC responded today with an assurance that, while it is monitoring closely a number of trusts about which it has concerns, it has no evidence that there is another trust in England at which it would take the kind of action that it took at Basildon.

Dr Foster, which has a partnership with the NHS Information Centre called Dr Foster Intelligence, specialises in healthcare data analysis.

Roger Taylor, director and co-founder of Dr Foster said: "Over the last nine years of the Hospital Guide we have seen a steady improvement in hospital performance but unacceptable variation between hospitals still exists.

"Dr Foster will continue to publish data in order to provide information to the public, drive improvement in patient care and save lives.

"Hospital trusts should use the guide to carefully investigate where problems exist, even those who have performed well.

"Patients and the public should use the Hospital Guide to help make choices about where they want to be treated, to ask the right questions of their health professionals and to hold hospitals to account."

Other trusts joining Basildon in Band One on the Dr Foster Patient Safety Score were: South London Healthcare NHS Trust, Weston Area Health NHS Trust, the Lewisham Hospital NHS Trust, University Hospitals Coventry and Warwickshire NHS Trust, Scarborough and North East Yorkshire Health Care NHS Trust, Hereford Hospitals NHS Trust, Mid-Yorkshire Hospitals NHS Trust, Blackpool Fylde and Wyre Hospitals NHS Foundation Trust, St Helens and Knowsley Hospitals NHS Trust, University Hospital of South Manchester NHS Foundation Trust and Tameside Hospital NHS Foundation Trust.

At the other end of the scale, University College London Hospitals NHS Foundation topped the Patient Safety Scores followed by Cambridge University Hospitals NHS Trust and Guy’s and St Thomas’ NHS Foundation Trust.