Patients are more likely to die at Barnet and Chase Farm hospitals than in any others in London, according to a study released over the weekend.

Barnet and Chase Farm Hospitals NHS Trust has the worst mortality rate in the capital, placing it in the bottom 15 in the country, a survey for The Sunday Times has found.

The trust's record on inpatient waiting times with only 65 per cent of patients admitted to hospital within six months of referral is among the ten worst in England, the survey said. It also claims the trust's record of ensuring just 68 per cent of outpatients see a specialist within 13 weeks of referral is among the bottom 20 in the country.

The study reveals patient death rates for 167 NHS hospital trusts in England, taking into account factors like age, sex and diagnosis. But Nick Samuels, director of communications for Barnet and Chase Farm, said errors in the guide it named Elizabeth Heyer as chief executive even though she resigned in February last year put question marks over its validity.

"Given the number of factual inaccuracies in the report, I have to question the accuracy of the mortality rates," said Mr Samuels.

"About one year ago, we took over health care for the elderly from the primary care trust. Obviously, with that cohort of patients, there is going to be an increase in mortality."

Mr Samuels added that data used in the survey was more than a year old. "The situation has dramatically changed since then.

"Over a year ago our waiting lists and waiting times were much longer. The benchmarks set by the Department of Health now show the trust in a favourable light."

A spokesman for the Dr Foster Unit at Imperial College London, which conducted the survey, said it stood by the mortality rate figure. "The inaccuracies in the report would not in any way put a question mark over the mortality figures, which are produced through official figures released by the Department of Health."

The trust is hopeful it will be awarded one star in the NHS ratings, which are released later in the year. At the end of March it was hitting Government inpatient, outpatient, A&E and cancer targets. However, a predicted £2.5million deficit means it will underachieve in one of the target areas.