Last month a judge awarded a Sydney mother $360,000 in compensation in a medical negligence case over the death of her newborn baby.

It was by no means a record pay-out, but it highlighted just how inadequate medical record keeping is in Australian hospitals.

By some estimates, as many as 18,000 people die every year as a result of medical error, while 50,000 people suffer a permanent injury.

But there is no systematic collection and linking of treatment error data, so it is impossible to know for sure how many medical mistakes cause serious harm or death.

Some people believe there is a silent epidemic of error in the Australian health system.

Lorraine Long set up the Medical Error Action Group almost 20 years ago. Between 70 and 100 complaints come to her each day, half of which she says can reasonably be classified as medical error.

"I think it's so difficult for people to believe that doctors make mistakes and the way it's been handled is, well, let's keep it quiet," she said.

"From what I've found, about one in 10 patients will experience a mishap. One of the most severe I've found is wrong site surgery, meaning the wrong eye, wrong leg, wrong hip, even the wrong patient.

Official figures relating to medical mistakes hard to find

"It's either complacency or it's lack of concentration or they just don't know and they are taking a gung-ho approach - we'll open them up and let's see what we find. But there is a degree of shoddy medical procedures that's worrying and that needs to be addressed immediately."

Official and accurate figures on deaths and injuries from medical mistakes are hard to come by. Less so are the real world stories of fatal error.

Bianca Jenns's father Benvenuto Comina died in hospital in December 2010 after being given medication he was allergic to directly before surgery.

"I realise there were mistakes made along the way, but that safety check is set up so that these things don't happen," she said.

Mr Comina was wearing an allergy wristband warning of his multiple allergies to Ventolin, morphine and an antibiotic, but the senior anaesthetist on the day did not check.

"And when he was asked at the coroner's inquest if he checked it, he just said he just didn't consistently check any armbands. So it wasn't part of his procedure to check armbands. He would occasionally, but not always," Ms Jenns said.

"That to me, was the last line of defence and he failed to do that, and that to me, that would have saved my father."

She said she was told her father had died from a heart attack.

"They said that they gave my father medication similar to what he was allergic to.

"That was the cause of death. They didn't say it was anaphylaxis, they said that it caused him to have a heart attack.

"They didn't say it was anyone's fault, they didn't say there was an error, they just said that's what happened. At that time I just couldn't understand how that could have happened if it was written in all his documents.

"The coroner found that he died from anaphylaxis, which caused a cardiac arrest eventually."

In 1995, the landmark Quality in Australian Health Care Study found the rate of so-called adverse events was 16.6 per cent among hospital patients, accounting for around 18,000 deaths and 50,000 cases of permanent disability.

The study's methodology and its conclusions have been hotly contested within medical, academic and political circles.

But Ms Long argues little has changed since the report was handed to the government in the 1990s.

Small percentage of complaints leads to negligence claim

"I don't see a reduction in medical error at all. I still see cover-ups, I still see the lengths health departments will go to smother things and destroy records. But the errors are just the same, I'm not seeing a reduction.

"And you would think that with all the recommendations made by coroners around the country, and those recommendations being paid attention to and implemented that systems would be better."

Lawyer Kathryn Booth, who heads Maurice Blackburn's national medical negligence practice, said the firm received hundreds of complaints every month from patients who have had medical treatment they were not happy with.

"Only a few of them will actually go on to have a successful medical negligence claim," she said.

"The law now is that you can only sue if you have a permanent injury, which is classified as significant, which means greater than 5 per cent whole body impairment.

"The types of cases we see, the common sorts of things that go wrong are in the area of obstetrics, emergency care, not recognising the seriousness of somebody's condition and being sent home, operative errors and of course, misdiagnosis."

She said the majority of complaints involved a small number of the same clinicians.

"About 3 per cent of doctors are accounting for 50 per cent of the complaints. That study means that there's a great opportunity for the regulators and the risk managers to achieve better outcomes in safety and substantially reduce the number of complaints about outcomes if they target the rogue 3 per cent of frequent flyers."

Ten years ago Australia introduced the world's first nation-wide open disclosure policy. It was designed to enable health services and clinicians to communicate openly and honestly with patients when health care does not go to plan.

In practice, it involves acknowledging adverse events, expressing regret and explaining what steps are being taken to manage the consequences.

But multiple studies have found health professionals remain deeply concerned about the legal ramifications of open disclosure, in particularly the legal liability.

The open disclosure policy has been reviewed and a new set of standards will be endorsed later this year.

The updated policy contains new elements, including an apology and for the word "sorry" to be part of that, but without making speculative statements or apportioning blame.