Patients who choose to stay in Class C and B2 wards in public hospitals will have to go through means testing.

All citizens and permanent residents will still be subsidised, but the subsidy amount will differ, depending on the patient's income.

The exact income criteria have yet to be fixed.

Lower-income citizens should not be affected. Their medical bills will continue to be subsidised by 80 per cent for Class C, and 65 per cent for Class B2.

Higher-income citizens will get a smaller subsidy, and will have to pay more.

Health Minister Khaw Boon Wan said that based on the current profile of patients in Class C and B2 wards now, the majority of Singaporeans should not be affected by means testing.

Percentage of Class C patients whose per capita household income is in:

Percentage of Class B2 patients whose per capita household income is in:

The size of the subsidy cut for higher-income patients has yet to be determined.

But Mr Khaw said that higher-income patients who stay in Class C and B2 wards will still get higher subsidies than if they choose Class B1 wards, which are subsidised by 20 per cent.

Patients can still choose any ward class they want.

But they will have to go through a means test if they pick Class C or B2.

If the test shows that they belong to a higher-income group, they will have to pay more than someone from a lower-income group.

The criteria and mechanism are being worked out.

But the hospitals' means testing system will not replicate the system being used at nursing homes and community hospitals, in which the financial status of the patient's entire family is assessed.

The hospitals' means test may assess just the individual patient's financial status, for instance, his average salary over the last 12 months.

This will probably be done via an automated system, for example, income declared to the Central Provident Fund Board or the Inland Revenue Authority of Singapore.

Those who are not working - retirees, housewives and children - may be assessed on the type of dwelling they live in.

But HDB flat-dwellers who do not work should not worry, said Mr Khaw, as they will probably still get the same level of subsidies.

All patients are charged the same fixed rate for immediate treatment at public hospitals' emergency departments, regardless of nationality or income level.

This charge is subsidised by 50 per cent.

It is so that those who can afford private care will not crowd out poorer patients, especially as public health-care services improve.

With rising expectations for better services, the Ministry of Health has been rebuilding public hospitals and upgrading services.

Mr Khaw said this narrows significantly the differences between subsidised and private wards, which attract demand for subsidised classes away from private ones.

Means testing is a filter the Government has to install, to ensure good public health care remains accessible to the poorer patients who, unlike the rich, have no other choice.

Mr Khaw added: 'The easiest thing for the Minister of Health is to do nothing. Just let public health standards drop. Then, automatically, those who can afford it will never think about going to public hospitals. Their first thought when they are sick is to go to private hospitals. So that is means testing, in a self-regulated way...

'But as a health minister, I judge myself based on the standard of care a poor patient receives, not what a rich patient receives.'