A proposed $6 ''co-payment'' for a GP could add $2 billion to the states' and federal government's health bills, modelling shows.
The South Australian Health Department has estimated that the co-payment proposal would lead to 4 per cent of patients forgoing their GPs and instead attending their emergency departments to seek help for minor health complaints.
The modelling showed that this would double the number of people presenting at emergency departments for minor ailments, tripling waiting times and costing an extra $145 million. Extrapolating the increased costs to the South Australian health system across the country, based on population, showed it would add $1.99 billion to the country's health costs. The Greens and Labor seized on the figures.
''They demonstrate that this proposal's going to greatly increase total health costs, rather than save the Commonwealth money,'' said Greens health spokesman Richard Di Natale.
Labor's health spokeswoman, Catherine King, said they showed the co-payment proposal should be ''knocked on the head''.
The co-payment suggestion came from Terry Barnes, a former adviser for Prime Minister Tony Abbott, who wrote a submission to the federal government's Commission of Audit for the Australian Centre for Health Research.
Mr Barnes wrote that the government could save $750 million over four years by forcing patients who are bulk-billed to pay $6 to visit their GPs.
He told a parliamentary committee last week there was ''at least anecdotal evidence'' GPs were being ''overused'' by patients.
He calculated there would be a 3 per cent reduction in the number of people seeing their GPs if a co-payment were introduced but acknowledged it was ''very hard to make assumptions''.
''There has been speculation and some analysis but there is no definitive work on it,'' he said.
The co-payment idea has found favour with many in the government, but doctors and health groups have criticised the idea, saying that patients will try to avoid the fee by using emergency departments.
Health Minister Peter Dutton opened the door to the introduction of a co-payment, telling the ABC on Thursday: ''I want to make sure that, for argument's sake, we have a discussion about you or me on reasonable incomes, whether we should expect to pay nothing when we go to see the doctor, when we go to have a blood test.''
This proposal's going to greatly increase total health costs.
On Saturday, he said the proposed co-payment was a suggestion from a think tank, ''which the South Australian Labor government has clearly wasted taxpayer funds on public servants' time on modelling''.