Researchers at UMC Utrecht have developed a calculation model to translate the results of large-scale clinical trials into individual treatment options. This enables them to predict whether a specific medical treatment works for you, as the model predicts life expectancy with and without the treatment. The study results were published in The BMJ.
Health care professionals treat large groups of people with risk factors to prevent a serious problem in just one of them. As all people are different, the average effect of treatment as shown in large-scale clinical trials does not apply to everyone. Professor Frank Visseren, an internist and vascular medicine specialist at UMC Utrecht, explains: "In 30 hypertensive individuals the blood pressure is lowered using medication to prevent serious vascular problems, such as a cerebral infarction. But only one of them will actually have that cerebral infarction, which means you're treating 29 patients to no effect. You just don't know in advance who that one person is. This calculation model helps to reduce over-treatment."
Statistical tricks
Internal medicine resident Jannick Dorresteijn reports that it is not only the focus on the individual that is new, but particularly also the prediction of gain in healthy life-expectancy. "This is possible due to a combination of new statistical tricks that we developed together with colleagues from Harvard University in Boston and subsequently applied to a clinical trial that had already been concluded and in which participants had been followed for as long as 17 years. This allowed us to also study whether the prediction was still correct after all this time. And it did; 100%. That makes it a very practical model."
Upside down
Because age is the key risk factor, risk tables for chronic progressive illnesses, such as cardiovascular diseases, always turn red for older people. As such, the prevailing view is that they stand to benefit most from preventive treatment. Dorresteijn: "Our predictions attack that sacred cow as young people with risk factors can be protected from these illnesses, while older people often just trade them in for another illness. If you look beyond the next decade, it becomes clear that there is a lot to be gained after that in terms of life expectancy for young people. We're turning things upside down." Visseren: "It's like your pension. You don't start saving up for that a few years before you actually need it. The sooner you invest, the greater the health gains."
Applicable
They would like their tool to help both the health care professional and the patient to make the right choice about any treatment. Dorresteijn: "This information is easy to explain. People do have an opinion on what one year's gain in life expectancy is worth, as opposed to the lowering of the risk that is currently often used as a reason to make a specific choice." Visseren adds: "We will add this tool to our vascular risk app, but essentially, you can apply the calculation model to all medical fields. A lot of data is available from large-scale clinical trials that you can use to make the right treatment decision for the individual patient."