IT is the envy of observers from elsewhere in the UK and understandably so.

Free personal care for the elderly, which was introduced in 2002, has benefited many thousands of older people in Scotland and embodies the dearly-held belief that the infirm should receive the same level of care and support regardless of their ability to pay.

Funding the policy, however, remains a vexed issue. The cost of providing personal care to people in their own homes has more than doubled in eight years, from £133m in 2003-4 to £347m in 2011-12, calling into question whether it is sustainable to continue providing it for free in the long term.

Health Minister Alex Neil was at pains yesterday to stress the positives, particularly the fact that the figures show a 42% increase in the number of older people being cared for at home in 2011-12 compared to eight years previously.

That is indeed a good thing. As The Herald has highlighted in our ongoing NHS: Time for Action series of articles, hospitals are under unprecedented and growing pressures due to the ageing population. Caring for more older people in the community when they have ailments or accidents, and preventing so-called "boarding" in hospitals, will be essential in order to ease that pressure. Not only does such an approach save money, but for most individuals it is less stressful and helps prolong their independence.

However, personal care still has to be paid for. By 2035, one in four Scots will be a pensioner, up from fewer than one in six today. The current figure of £458m per year for the cost of funding free personal and nursing care at home and in care homes, will increase significantly by then.

So how shall it be funded? There are no easy answers, given the NHS's finite resources, a truth recognised by all parties at Holyrood, which is why Scottish Labour – the architect of this policy – has stressed the need for a national debate on how to care for the growing elderly population.

That is exactly what is required. As part of that debate, it will be necessary to consider, frankly and without prejudice, whether it is fair to expect taxpayers of working age, struggling to get on the housing ladder and repay tertiary education loans, to fund free personal care for all older people, or whether those pensioners who could pay, should pay, in order to protect free provision for those who cannot.

That is not the only aspect of healthcare provision that must be publicly discussed. Dr Brian Keighley, chairman of the BMA's Scottish Council, emphasises in today's Herald that any debate on the future of the NHS should consider whether some hospital services should be concentrated in fewer sites. He is dismayed that politicians' tendency to focus on short-term targets like elections makes it difficult to take such tough decisions related to long term planning for the NHS. For that reason, he suggests the NHS might be made independent of politicians, much like the BBC. The idea that the BBC's nominal independence frees it from political pressure would no doubt raise a few eyebrows among the corporation's trustees and board members, but Dr Keighley makes a highly pertinent point.

The overarching issue where both free personal care and configuration of hospital services is concerned, is that of funding. Unchecked and unmanaged, with the population ageing, the NHS will simply become too expensive.

A public debate is urgently required, with patients and their families at the heart of it, to set priorities and work out what shape the Scottish NHS should take to make it sustainable.