David Cameron is right. The NHS must change as the population and its health needs change. Yet this is what it has been doing since its inception. Once orthopaedic (literally child straightening) surgeons spent their days treating young people misshapen by polio and spinal tuberculosis. Now they replace the joints of old people disabled by arthritis. Cardiac surgeons once treated hearts damaged by rheumatic fever; now they treat hearts damaged by poor diets and smoking. These and many other health professionals and managers have never had any illusion about the need to change and even, when called upon, to do so quickly. The emergence of AIDS in the 1980s gave rise rapidly to new approaches to infection control, data protection, and patient involvement, as well as major reconfigurations of hospitals, first to open new dedicated AIDS wards and then, as treatment became available, to close them. The question is not whether the NHS must change. Rather it is what it must change into.

The government’s current proposals provide little clarity. The 450 page Health and Social Care Bill is written in a way that would deter all but the most persistent, with its seemingly endless list of changes to words in previous legislation making it almost impossible to understand what is being proposed. Inevitably, many people simply assumed that it would reflect what was set out in the preceding White Paper. That made many reasonable points, such as the need for more clinical engagement. Yet, when a few dedicated individuals did manage to plough through the text of the Bill it was clear that what was being proposed was very different indeed. Many will agree with Liberal Democrat MP John Pugh who described a "vision of a bill being drafted during the daytime by a sane, pragmatic Dr Jekyll-like minister, but during the night some … Mr Hyde jumps in with a rightwing ideology, breaks into Richmond House and changes many of the sentences." It was not even clear what problem the reforms were trying to solve as the government’s “dodgy dossier” on cancer and heart disease that sought to justify change was rapidly discredited.

So what are the challenges facing the NHS in the future? The Prime Minister has now abandoned his claim to have ring-fenced the NHS budget and admits that his main goal is to cut it by £20 billion, much of which must go before his reforms can be implemented. He sees his task as complicated by an ageing population, which he blames for driving costs upwards. Yet he overlooks how we are living longer in good health and that the main driver of expenditure is how close we are to death, whenever it occurs, rather than how old we are.  The real challenges posed by an aging population are how to promote healthy aging through lifestyle changes and how to manage the combination of chronic disorders that we will accumulate, but which advances in treatment now allow us to control. A typical 80 year old may have five or six conditions each requiring specific treatment, involving a wide range of health professionals in different facilities, all of which must be co-ordinated. But this is only the start. We can begin at the other end of the age spectrum, where again we see the effects of medical advances. No longer do we have wards full of children with jaundice and chest infections. The NHS must now look after children with chronic diseases, such as diabetes and genetic disorders, cancer, and a wide range of behavioural disorders and must manage their transition to adulthood. Then there are those whose numbers are likely to increase as a direct consequence of the government’s other policies. These include homeless people, hit by a combination of rising unemployment and reduced welfare benefits, and those with mental illness. Suicides are already up almost 8% from 2007. One word, complexity, encapsulates the needs of all of these groups. The NHS of the future must be able to provide a comprehensive, integrated service through which those with complex disorders are able to navigate with ease.

So how can the NHS create such a system? A first step is to achieve integration. This requires some organisation responsible for ensuring a comprehensive package of care for everyone living in a geographically defined population, whether they live in a home or on the streets, and whether they have registered with a GP or not. That organisation, even if it is no longer called a Primary Care Trust, must work with health care providers to ensure that appropriate, evidence-based services are in place and must monitor the results they are achieving. This will often mean the establishment of networks, such as those that have achieved major advances in cancer care but which have been threatened (their recent reprieve raises enormous questions about how this is compatible with the free market envisaged in the government’s reforms). These networks must include all providers, avoiding imposing artificial divisions between general practitioners and hospitals. It will require clarity about training, to ensure that skilled staff are available. It will require embedded public health expertise, with efforts devoted to prevention as well as to cure. Finally, it will also mean avoiding quick fixes, such as primary care walk-in centres and Independent Sector Treatment Centres that may undermine the viability of specialist services.

A second step is to build in the flexibility required to respond to changing circumstances. This means finding some solution to the ruinous Private Finance Initiative deals that have locked hospitals in stone for 30 years or more. It also means revisiting the idea of Foundation Trusts. At present, to transfer services from one hospital to another it is seems necessary to merge them into a single Trust. When circumstances change again, as is already happening in London, it may be necessary to break them up and merge them with other Trusts.  Yet we know that organisations on this scale take several years to recover their previous level of performance. It will exclude the big corporations with their one size fits all approach but it does allow involvement by non-profit organisations that have brought responsiveness and innovation into niche areas, such as palliative care and substance abuse. And it requires avoidance of disruptive large-scale reorganisations that divert managerial attention from the real problems. Just like football teams, hospitals do better when they have managerial stability.

Unfortunately, the proposed reforms take us in the opposite direction, to commissioners responsible only for those who register with them, purchasing only those services they think appropriate while avoiding anyone whose problems are “difficult”, and to providers competing for whatever services are most profitable. We don’t need a crystal ball to see the consequences. We need only look to the USA, where such a system is in place. There it is those with complex needs who suffer. Someone with diabetes is five times more likely to die before the age of 40 than in the UK. And it won’t save the money the Prime Minister wants. The American health system costs almost twice as much as a proportion of national income as the British one yet still fails to provide coverage for over one in seven people.

Unfortunately, there is now a danger that the model that will emerge from the current listening exercise will be a political compromise between the two coalition parties, designed to avoid either loosing face with their supporters. This is no way to design a health system. The only sensible course is to go back to the drawing board, agree what problems we are trying to solve, and design a system that is fit for purpose in the 21^st century. Paradoxically, it may turn out to look rather like what was in place in the 1980s, before an internal market was even thought of, but with the possible inclusion of social care. And once the new system has been put in place, then perhaps it can be left alone, so that those working in it can get on with adapting successfully to changing health needs, just as they have done in the past, rather than to changing political whims.