London - Scientists have devised a test that can predict whether someone will live for another five or ten years.
The test – which is 83 percent accurate – assesses how long a patient is expected to live by measuring levels of 14 "biomarkers" in the blood.
Taken together, the findings could eventually lead to a blood test that could warn people they do not have long to live – and encourage them to adopt a healthier lifestyle.
Researchers tested 44 168 people aged between 18 and 109, of whom 5 512 people died during their study.
The 14 biomarkers they identified are compounds in the blood linked to various biological processes.
They include chemicals linked to processing of fats and proteins, as well as levels of inflammation.
The scientists found the test could predict with 83 percent accuracy whether someone was likely to die in the next five years and ten years.
The test is around 10 percent more accurate than other existing predictors of life expectancy, they said.
The researchers, Dr Joris Deelen, of the Max Planck Institute for Biology of Ageing in Cologne, Germany, and Professor Eline Slagboom, of Leiden University in the Netherlands, made clear that mortality is not set in stone. Once patients realise that they have a poor life expectancy, they could take steps to improve their chances of living longer.
Dr Deelen said: "It’s a marker of your current health and physical vulnerability. The test does not predict how long you will live as you have a hand in it yourself.
"If the blood test indicates your physical vulnerability, if it tells you how long you’ll live, and your family see that and you change your lifestyle, you may live twice as long."
The researchers say their test could also be used in medical research.
For instance, the effects of a drug on a vulnerable patient could be different to that on a more robust patient with a longer life expectancy.
Commenting on the research, Dr Amanda Heslegrave, of UK Dementia Research Institute at University College London, said: "The large numbers in this study makes the data more viable. However, it is limited by the fact that being only European data it may not apply to other ethnic groups without further studies.
"Whilst this study shows that this type of profiling can be useful, they do point out that it would need further work to develop a score at the individual level that would be useful in real life situations. So, it’s an exciting step, but it’s not ready yet."