One in four people globally will have a stroke at age 25 or older, according to a study published Wednesday in the New England Journal of Medicine.
Researchers from the Institute for Health Metrics and Evaluation studied global, regional and country-specific lifetime risks of stroke in 1990 and again in 2016, then compared them. They found that the risk of stroke from the age of 25 onward was 24.9%, up from 22.8% in 1990.
This includes risk of first-time stroke, ischemic stroke and hemorrhagic stroke, the researchers explained.
“We calculated the lifetime risk only among persons 25 years of age or older because incidence rates of stroke among younger persons are low and are less dependent on modifiable risk factors and on the characteristics of health systems, which are associated with stroke burden in older populations,” the study says.
Dr. Gregory Roth, the study’s author and assistant professor of health metrics sciences at the institute, said that what he found most striking is that “there are places you can live where stroke risk is much, much higher than it needs to be.”
Overall, the regions with the highest risk of stroke were in East Asia, Central Europe and Eastern Europe, whose risk went up to 38.8%, 31.7% and 31.6%, respectively. The United States had a risk between 23 and 28.9%.
Those at greatest risk, the report found, were men in China – whose risk went up to 41.1% – and women in Latvia – whose risk went up to 41.7%.
China was also the country with the greatest difference in risk between men and women; women the risk was 36.7%.
Meanwhile, the risk in Central Asia, southern and tropical Latin America, high-income Asia-Pacific and southern sub-Saharan Africa decreased significantly between 1990 and 2016. Sub-Saharan Africa had with the lowest risk of stroke.
Roth said stroke risks were higher in certain areas due to how the culture “encourages or discourages different subgroups.”
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He said government and health systems need to help better educate communities on how to plan to improve their health.
“The challenge is that we’re asking people to look 50 years or more into the future and people find that quite difficult – they have pressing urgent concerns well before then,” Roth said.
“The kind of modifiable risk that will have the biggest impact are changes for eating a healthier diet, increasing physical activities, avoiding tobacco, keeping a healthy weight throughout your life, keeping a normal blood pressure.
“We need to start conversations with our patients and our family members and our communities far earlier in life. It’s much easier to avoid developing these risks, then to get rid of these once you have them.”
Jeremy Pearson, associate medical director at the British Heart Foundation, wrote in an email that “This concerning analysis further highlights the devastating impact of stroke and the shocking statistic that one in four men and women around the globe will suffer a stroke in their lifetime.
“The study shows that overall the risk of stroke in the world’s richest countries is lower than the global average, which may be a result of healthier lifestyles and better use of preventive treatments – such as blood pressure lowering drugs – than lower income countries,” added Pearson, who was not involved in the research. “These international inequalities need to be addressed.”