And one in 20 deaths led to significant criticism of the care given to the patient, according to the Australian and New Zealand Audit of Surgical Mortality.

In about 1 per cent of cases clinical problems were found to have probably caused the death.

Audit chairman Guy Maddern said the potential problems were those where it might have been possible to tackle the problem differently. ''It may have been that a scan should have been done earlier or an antibiotic prescribed, it may not have made any difference but with the benefit of hindsight we have identified it,'' he said.

The audit, run by the Royal Australasian College of Surgeons, examined more than 10,000 deaths in three years. It found that most problems were delays in treatment, or the decision to operate at all.

Professor Maddern believed the audit, in its third year, could prevent patient deaths. In Western Australia, where an audit has run for about 10 years, deaths seemed to be decreasing.

''What might be happening is we might be finding surgeons who are realising it might not always be necessary to do [surgery],'' he said. ''Often these patients are put in front of a surgeon and they feel obliged to do something, and this audit is giving them the confidence to say 'This surgery is not going to provide a meaningful solution'.''

In most of the audit areas the national figures showed improvements, and the vast majority of deaths involved no significant criticisms.

The proportion of surgeons participating rose dramatically from 60 per cent last year to 90 per cent this year.

But Professor Maddern criticised private hospitals in New South Wales and Queensland that were slow to participate, despite the NSW government now funding the process.

Other problems identified in the audit included patients not being moved into a critical care unit.

Patients had also missed out on preventive treatment for blood clots, and experienced delays in transport to other hospitals.

''Most of these deaths are occurring in the older age groups, and they have many co-morbidities … the surgery is in many ways the easy part, it's managing these other conditions in the post-surgical period that is extremely complex,'' Professor Maddern said.