A recent survey shows that more than 1.6 million Australians are pushed to drop private hospital cover with the proposed changes to the health insurance.

Market research company ANOP and consultant Deloitte probed health insurance members about the federal government's plan to means test the 30 per cent rebate.

The account denied Treasury's forecast of 25,000 consumers letting go of their private health cover in the first year as the changes come in.

On Wednesday, ANOP chairman Rod Cameron said in an interview in Canberra, "You are looking at very significant percentages that are going to drop or downgrade for hospital and even bigger numbers in terms of dropping or downgrading their extras cover.”

According to the report, 1.6 million insured Australians would drop private hospital cover over five years while 4.3 million are expected to downgrade their policies.

Chief executive Michael Armitage of Australian Health Insurance Association (AHIA) said the government had underestimated the probable impact of this policy.

"In an attempt to find savings, the government has developed a policy which will demand a greater financial injection than it saves in order to repair the health system," Armitage conveyed.

Labor has tried to means test and has trimmed down the rebate for individuals earning more than $75,000 a year and couples earning more than $150,000 annually.

The plan has been blocked by the Senate but can gain the possibility to be passed if the Australian Greens take the balance of power in the upper house starting July 1.

Through changes to private health insurance procedures, the government will be declaring savings in the budget of around $2 billion over four years.

Health Minister Nicola Roxon said the government rejected claims by AHIA of 1.6 million Australians dropping hospital cover because of means-testing of the private health insurance rebate.

"The findings are based on general questions being asked of 2000 people via a telephone poll without all the relevant financial information available," Roxon explained.

"People don't make decisions about family budgets during telephone polls. They make them in a more considered fashion with all the facts available," Roxon added.

She defended that means testing the rebate was fair as 90 per cent of lower-income adults should not subsidize private health cover for the top 10 per cent.

"People who are going to drop out or downgrade their private health insurance are the more healthy and younger (people), leaving a less healthy pool in the privately health-insured population," Cameron said.

Deloitte estimates the policy change would augment private health insurance premiums by 10 per cent more than otherwise come 2016.

Opposition health spokesman Peter Dutton said the coalition had impeded the proposed modifications as there would be effects to the public system.

According to Dutton, "It also shows that our public hospitals will be swamped with close to an additional million admissions above normal growth over the next five years and that the costs of that to the taxpayer will be billions of extra dollars.”