The choice between a private system for the minority and a public system for the rest - both underpinned by Medicare - has been limited. Treatment standards have remained roughly uniform, led by doctors who often work in both public and private hospitals.

That cosy accord faces a challenge. For the first time, prospective patients at one private hospital chain will be able to see how its hospitals compare with public hospitals on measures such as infection control.

The move by Healthscope, Australia's second-biggest hospital company, strikes at a tender point for public hospitals, which are increasingly reliant on income from private patients treated in public hospitals.

According to the Healthscope figures, which are collected on the same basis as those for public hospitals, their patients are at significantly lower risk of suffering hospital acquired infections, experiencing a fall while in hospital and of having to undergo repeat surgery.

While hospital-acquired infections remain relatively infrequent, they occur often enough for chronic hospital users to feel a pang of additional anxiety about the chances of catching a unwanted superbug.

The national target is to keep such infections under the rate of two cases per 10,000 patient days. Healthscope hospitals report a rate of 0.36 cases per 10,000 patient days while Victoria's public hospital rate is more than twice that and NSW's more than three times.

Few other enterprises routinely collect as much information as hospitals about daily performance but release so little for outsiders to assess.

Healthscope's chief medical officer, Dr Michael Coglin, says the company's decision to go public was party a recognition of the inevitable momentum towards disclosure of performance information previously hidden from the public.

Coglin challenges the argument quality reporting works unfairly against public hospitals, which have to deal with more complex and urgent cases than private hospitals, which he says now perform complex surgery and other services well beyond ''lump and bump'' surgery.

Now public hospitals are accepting a growing share of private elective surgery, it is only appropriate, he says, patients, doctors and staff are told how their performance compares with private hospitals.

Growth in demand for hospital openness - a trend credited with inspiring better patient results - is belatedly catching on in Australia.

The Healthscope disclosures follow the release last week on the federal government's MyHospitals website of the first individual public hospital results on the gritty topic of golden staph bloodstream infections.

The figures are not great for some high-profile institutions such as Melbourne's Peter MacCallum Cancer Centre and Sydney's Westmead Hospital, where ''germ counts'' exceeded the national benchmark.

Health services experts Professor Jeffrey Braithwaite, of the University of NSW, and Professor Russell Mannion, of Birmingham University in Britain, are sceptical about public reporting improving performance.

Experience with public reporting systems had shown it was ''very tricky to get the balance right'', they wrote in the Medical Journal of Australia recently.

That is disputed by two Sydney University medical school experts, Associate Professor Christine Jorm and Professor Michael Frommer.

''It is secrecy that corrupts,'' they say. Opponents might counter that revealing how hospitals are performing distorts hospitals' behaviour, such as neglect of high-risk patients in order to meet caseload targets.

But Jorm and Frommer say the evidence of this is scarce. In Britain, a study of 27,000 patients who had cardiac surgery showed, after the introduction of performance reporting, the death rate fell, and there was no evidence surgeons were overlooking high-risk patients.

Jorm told the Herald the private-public hospital performance figures should be welcomed for improving consumer awareness, but should not be taken as an indicator of inferior care in public hospitals. She says there are a range of reasons public hospital patients are less likely to fare as well as those in private patients.

Public patients will include more poorer and less educated patients, who statistically tend to be sicker, more often suffer multiple chronic illnesses, more often be smokers and less often have the support and education that favours the better off.

But the federal government says it has coaxed state governments to agree on the national reporting system, not just to improve patient care. More effective care and shorter hospital stays will generate hundreds of millions of dollars in savings.

Coglin says his company's experience with internal performance reporting has brought improvement in patient outcomes. ''Public reporting will only enhance this.''