Patients visiting their family doctor may soon to be able to see at a glance how altering their lifestyle could prolong their lives.

Dr Chris Martin, who combines being a GP in Laindon, Essex, with research, has created a computer program that predicts how long an individual can expect to live, based on simple data such as blood pressure, cholesterol levels, smoking habits, age and past medical history.

The output is in the form of a graph that shows how many more years could be achieved by changes. The most obvious is giving up smoking, which affects the risks of heart disease, lung cancer, and chronic obstructive pulmonary disease.

But the program can also illustrate the benefits of lowering blood pressure and cholesterol, and maintaining control of type 2 diabetes.

Doctors already use a risk calculator to assess how likely their patients are to suffer a heart attack, but Dr Martin’s program, which he calls the Laindon Model, goes further. Once a patient’s data is entered it produces a picture of the risks, and the effects that different courses of action would have on reducing them.

For a 42-year old who smokes and has high blood pressure and elevated cholesterol, for example, a GP might say: “Mr Smith, your risk of developing cardiovascular disease is 13.2 per cent. If you were a non-smoker it would be 7.7 per cent”.

But, says Dr Martin, a substantial proportion of the population do not really understand percentages. Using his model the GP would show Mr Smith a set of curves on a computer screen.

These show the chance of still being alive at any future age, up to 85, and how that would be improved by giving up smoking, cutting blood pressure, or other changes.

The curves show that without changes, the chances of reaching 85 are less than 10 per cent. Giving up smoking would triple the chances of reaching that age, to about 30 per cent.

Choosing a lower age, the curves show that Mr Smith’s chances of reaching 70 are just under 60 per cent, if he changes nothing. But giving up smoking would increase that to 80 per cent.

A separate plot shows that controlling blood pressure would also have benefits, but less dramatic ones. In this case the chances of reaching 70 are raised from just under 60 to almost 70 per cent.

“It is visually striking how lethal smoking is, but not only that, it effectively puts into perspective the importance of stopping smoking compared to treating blood pressure” said Dr Martin.

He validated the system by using data from a group of people from Whickham, a town near Newcastle upon Tyne. Information was gathered between 1972 and 1974, from a sample of people chosen to be representative of the population as a whole. They were then followed up for 20 years by the authors of the original study.

Borrowing this data, Dr Martin fed it into his model, which predicted how many would have survived for 20 years. The model predicted 75 per cent; the follow up study showed the real figure was 75.4 per cent, impressive confirmation that the model works.

He believes its main use will be for GPs and those giving health promotion advice. “If you show patients a graph it really brings it home to them,” he said.

Health Enterprise East, the NHS innovation hub for the East of England, has taken it up and is promoting it. It is already in use in some GP surgeries in south Essex.

Dr Martin sharpened his computer skills on a course in Health Informatics at University College London, where his model formed the subject of his dissertation. The course, which leads to an MSc, is designed to help doctors, nurses, health managers and others to harness IT skills to improve patient care.

Explore Health News

• Swine flu

Times Recommends

• Charles blazes trail as sun king
• Thalidomiders win payout 50 years on
• Libel gag on talk of 'medical hurricane'