OUT of pocket medical expenses are set to go down as Health Minister Khaw Boon Wan continues to tweak the Medisave and MediShield schemes.

By March outpatient treatment for asthma, and possibly chronic obstructive pulmonary disease (COPD) which largely affects heavy smokers, will be able to be paid for in part with Medisave.

From April, about 40,000 cancer patients will be able to draw up to $600 a year for outpatient magnetic resonance imaging (MRI), computerised tomography (CT) or Positron emission tomography (PET) scans.They are expected to withdraw a total of $25 million a year.

The minister has also started work to further tweak the national medical insurance scheme, MediShield.

The last time he made changes to the scheme about three years back, co-payment for bills that are $10,000 or more for subsidised patients fell from about 60 per cent to 40 per cent. He now wants to halve that.

'I really want to bring co-payment down to 20 per cent,' promised the Minister, who hopes to bring this about with a premium increase of about $10 a month for the majority of people.

Speaking to reporters after donating blood at the Blood Bank on Tuesday morning, Mr Khaw said he has been studying the large bills some subsidised patients are still faced with - in spite of the huge government subisidy and insurance payment.

He has pinned this down to two factors. One is the daily limit which does not take into account the high cost of intensive care treatment for the critically ill.

The other is the expensive implants, expecially for orthopaedic treatments.

He said: 'Orthopaedic patients are increasingly using more expensive implants. They are better for the patient, and we increase the withdrawal limit, it would benefit them.'

Following many requests from patients with chronic ailments, the ministers will also allow Medisave to be used for more diseases.

He said: 'Just as safaris have their Big five (the must see animals are the lion, leopard, rhino, elephant and buffalo) chronic diseases also has its Big Five (high blood pressure, high cholesterol level, stroke, diabetes and asthma).'

Up to $300 per Medisave account a year can already be used for the first four. Adding asthma will complete the group.

The annual withdrawal limit for asthma will be announced later, as he is still gathering data on the cost of treatment.

Mr Khaw added that he is thinking of extending Medisave use to other chronic illness where early treatment or proper maintenance can keep people out of hospital.

Preventing expensive hospital stays in the future is the only justification for allowing Medisave to be used for outpatient chronic care, he said.

That is why he does not want to include mental illness or diseases like lupus or psoriasis, since it may solve the outpatient costs, but does not prevent hospitalisation.

In his on-going dialogue sessions with people on the scheme uppermost on his mind these days - means testing at public hospitals - Mr Khaw said he has shifted the focus from the amount of subsidy to the need for insurance.

He has been telling people who are in the mid to higher income levels to buy more than the basic MediShield scheme.

About 60 per cent of the 2.8 million MediShield subsicribers already have enhanced schemes. But Mr Khaw said he suspects another 10 to 20 per cent need more coverage.

Under the proposed means testing, people whose incomes are at the 50th percentile or less will continue to enjoy the current subsidy. Higher income-earners will get less subsidy.

He is waiting for the latest statistics to decide the cut-off salary. But he promised to round the figure up so it's actually higher than the 50th percentile.

'You have a very compassionate Health Minister,' he said with a grin.