The National Health Service's "best-performing" health authority has admitted producing misleading figures which placed it top of a national league table.

The National Health Service's "best-performing" health authority has admitted producing misleading figures which placed it top of a national league table.

It claimed to have cancelled no operations last year, but in fact had cancelled 258. Had it produced accurate figures, it would have slipped 43 places down the table of 99 English health authorities.

Last night, the revelation triggered fresh criticism of the league table system. It also placed a question mark over the Government's decision, announced in last week's NHS National Plan, to link hospital funding to efficiency measured in performance tables.

Barnet Health Authority topped the performance tables with no cancelled operations for the 12 months to March this year. But its two hospitals at Barnet and Chase Farm, both in north London, actually cancelled a total of 258 operations. Last night, the authority conceded its figures were wrong.

Alan Maynard, Professor of Health Economics at York University, said the NHS was a "very long way from collecting useful qualitative data on what it does and who does it".

He said: "Managers are too busy running around fighting fires and dealing with short-term crises to collect meaningful data. When they send in figures for league tables they are skating on thin ice, and you can get the problems like the authority in this example.

"If you don't have quality data you really don't have the basis to make meaningful decisions. The NHS information technology system is a mess."

In a statement, Barnet Health Authority said that cancellations did not appear in NHS performance figures because of confusion among managers about the way patients were pre-warned about potential cancellations.

But the statement insisted the hospitals had taken "immediate steps to review the way the figures are recorded to give a more accurate picture".

One of the patients involved, 89-year-old Mary Hale, had her hip-replacement operation cancelled five times. Mrs Hale was finally operated on in December, but it was a failure - her right leg is now shorter than her left, and she is confined to a wheelchair.

According to a National Audit Office report earlier this year, cancellation rates are going up across the country. More than 56,000 people had operations cancelled last year.

Experts fear this is the tip of an iceberg. Elizabeth Manero, chief officer of patient watchdog group London Health Link, said: "Operations cancelled before the day of admission, even repeatedly, are not centrally monitored.

"The way data is collected suggests that it is only last-minute cancellations that are symptomatic of poor service. This ignores the real distress caused to people who are already ill by the cancellation of an operation for which they have waited a year or more."