Five of the peak specialty medical groups has identified 24 tests and treatments that physicians and patients should question in a national campaign that aims to influence treatment standards in hospitals and medical practices across Australia.

Each college or association has listed five examples, including tests that lead to false positives or expose patients to radiation without generating a useful diagnosis and treatments that new research has proved ineffective.

Among them are the routine use of CT scans for patients admitted into emergency departments with head injuries, X-rays for lower back pain and testing the urine culture of elderly patients who do not have symptoms of a urinary tract disease.

The College of General Practitioners nominated the long-term use of proton-pump inhibitors to treat stomach acid and reflux, which has experienced a 9 per cent annual increase in prescription volume and cost $450 million last financial year, but can potentially lead to adverse effects.

The Australasian Society of Clinical Immunology and Allergy nominated food allergy tests such as pin pricks in patients where there is no evidence that allergies play a role in their symptoms.

The Australian College of Emergency Medicine's immediate past president Sally McCarthy said 40 to 60 per cent of diagnostic tests were of little or no benefit to patients.

"It's phenomenal, so it's in everyone's interests to not waste resources by diverting them to stuff that doesn't need to be done," Dr McCarthy said.

Most of the tests and treatments identified by the colleges were known to be ineffective, but junior doctors and nurses could be more prone to ordering unnecessary tests because they did not want to miss anything, she said.

"One benefit of having a list like this is that it empowers clinicians," Dr McCarthy said.

"But also, for patients, it gives them the information they need to challenge their doctors."

The Choosing Wisely campaign, co-ordinated by the not-for-profit organisation NPS MedicineWise, has been modelled on an initiative of the same name launched in the United States in 2012 and has since been adopted in Canada, Italy, the Netherlands and Germany.

NPS MedicineWise chief executive Lynn Weekes said few items on the list would be controversial among clinicians, but many recommended them anyway.

The aim of the campaign was to start a conversation.

"But doctors are careful, they're worried that they're going to be sued, they do practise a bit of defence medicine," Dr Weekes said.

"It may be the system is putting pressures on them in terms of the way the hospital works that just makes this the easier route. So it's a combination of factors."

An analysis of 26 low-value healthcare practices in the United States estimated that up to $8 billion was being wasted on those procedures annually, according to a JAMA Internal Medicine report published in 2014.

The report's co-author, University of Sydney Associate Professor Adam Elshaug​, said that would equate to more than $500 million if translated directly to Australia.