Paul has offered three suggestions on what I could talk about tonight.

First, an article in the Financial Times by Martin Wolf, about increased longevity, then a note on low productivity in hospitals and universities, and a third article about private health insurance and private hospitals on the Pearls and Irritations website by John Menadue. To these I could add another recent article on Pearls and Irritations by Steve Leeder, titled Keir Starmer may fix the NHS, but wholesale change is needed in Western societies for better health.

I’m happy to talk about health productivity, and the role of private health care, if there’s time, or in question time, but I was particularly taken by the piece by Martin Wolf, which fits well with Steve Leader’s piece and with the recent report of the House of Reps committee inquiring into the state of diabetes in Australia, chaired by a Labor backbencher, Dr Mike Freelander.

Martin Wolf’s piece is entitled Increased longevity will bring profound social change. He justifiably reminds us of, and celebrates, what he says is humanity’s greatest achievement: that life expectancy has roughly doubled over the past 180 years since the industrial revolution.

He rightly attributes this to the huge reduction in early childhood deaths arising from cleaner food and water – public health – vaccinations eliminating many deaths through contagious diseases, and antibiotics and other advances in medical science. Greater material prosperity has greatly reduced malnutrition. This has come with a need for much greater public spending on the healthcare of an ageing society – a bill we should be happy to pay, particularly if it gives most of us longer, healthy lives.

But it does bring challenges. Martin says “we must not shuffle a huge proportion of our society into unproductive and unhealthy old age. We can and must do far better, both individually and socially. How will people age? Will they enjoy a vigorous old age and then drop dead suddenly, or will we live on ‘sans eyes, sans teeth, sans everything’ for many helpless, hopeless years.

Martin points to the effect of income and wealth inequality, or what epidemiologists call “the social gradient”. In the US, we’re told, life expectancy between the richest 1 per cent and the poorest 1 per cent differs by 15 years for men and 10 years for women.

Wolf notes that one of the responses to the cost of ageing and the potential pointlessness of later life must be a later retirement age. He says “the idea of 25 or so years of education, 35 years of work and then, say, 35 years of retirement is impossible, for both individuals and society”.

But he – and the author he quotes – makes another key point, saying we need to avoid the situation we seem to have reached, where we tend to fall slowly apart. But maybe we can mix better diet, more exercise and medical advances to increase the quality of life in old age. We should not go on treating or, worse, merely managing the ailments of old age, but see to prevent them.

That’s the main point I want to make tonight. We need to put far more emphasis on prevention. It’s actually more important than continuing medical advances.

It’s widely assumed that longevity will continue indefinitely but, though my quick reading didn’t notice any authorities saying this, I suspect that the twin “epidemics” of obesity and diabetes could easily stop or even turn around the trend to ever-improving longevity.

A point Martin and Steve Leader make forcefully is that, though there’s an obvious role for GPs and other primary carers to promote prevention, it’s not primarily a job for the medical profession. For one thing, we’re talking about the social gradient, which calls for reduced inequality of income and wealth. As well, the main instruments for improving diet and exercise are not wielded by medicos.

This brings me to Mike Freelander’s parliamentary report on diabetes. His report asserts that “the primary aim must be prevention, and it is very important that every strategy possible is used as part of a comprehensive preventative response, requiring an all-of-government approach. Some of the report’s policy recommendations include improving access to healthy foods, using a reformulation levy to decrease consumption of sugar sweetened beverages, limiting advertising of high sugar and highly processed foods – particularly to children, better urban planning to encourage increased physical activity and improved educational resources for our children about the dangers of diabetes.”

There is plenty of overseas evidence that these measures work.

Next is the piece by Steve Leeder. He points to the NHS’s dire need for more funding – and to the growing reluctance of governments to ask taxpayers to cough up the money needed. In theory, the NHS could be made more efficient – its productivity could be improved, so it could use an unchanged quantity of inputs to produce an increased quantity of outputs – but decades of trying to improve the way the NHS is organised have failed to deliver.

So, Steve argues, maybe what Britain needs is a completely separate institution dedicated to greater prevention. “Sir Michael Marmot, one of Australia’s finest exports to the UK and a valiant crusader-epidemiologist,” he says, “speaks of health and illness in social context repeatedly and persuasively. He argues that changes are needed in all of society to improve health. These have worked to a fair extent in relation to smoking – education, legislation, taxation and advertising – all play a part, and all are outside the health portfolio. Community action around diet and exercise, fostered by local enthusiasm, can change things.” Steve says.

Further: “Gains in reducing the road toll owe much to advocacy from surgeons, improved roads, safer vehicle design, laws against alcohol, speed cameras and more – again, most outside the health portfolio. (As well, improved trauma services now use the “golden hour” after an accident to better effect.)

Winning community support for immunisation depends on education and advocacy, certainly health-informed but addressing social attitudes beyond the hospital or surgery walls. And then there is mental health – the determinants of which include biology, but social and family environment offer opportunities for preventive action.

Medicos – including medicos in parliament – have an important role to play in urging and advocating measures by governments and the community to prevent such things as bad diet and exercise.