Strokes in adults aged 20 to 54 rose from 34 to 62 per 100,000 between 1993 and 2020 in a US regional study

Stroke has been getting rarer in older Americans for decades. In people under 55 it has been heading the other way. A study that has counted hospital-treated strokes in one region of Ohio and Kentucky in selected years since 1993 found that the rate in adults aged 20 to 54 nearly doubled by 2020.

The numbers remain small. In 2020 there were about 62 first strokes for every 100,000 young adults, up from about 34. Among older adults in the same counties the rate fell over the same years, and it is still more than seven times as high.

The study was published on September 23 in Neurology by a team at the University of Cincinnati. It records the trend with unusual care. It does not explain it.

How strokes in young adults were counted

Most figures on stroke come from hospital billing records or from surveys that ask people whether a doctor has ever told them they had one. This study works differently. For selected years, its staff review the medical records of every possible stroke in a defined area. Hospitalized stroke cases in a 5-county region were ascertained and adjudicated by stroke-trained physicians in 6 study periods, adjudicated meaning that a specialist decided whether each case was a true stroke. The periods were 1993-94, 1999, 2005, 2010, 2015 and 2020.

Young adults were defined as individuals who were aged 20-54 years. Incidence rates were generated using US Census data standardized to the 2010 population, so that a change in the age mix of the region would not show up as a change in the rate. Incidence means new cases.

Across all six periods there were 2,076 first-ever strokes in young adults.

How much stroke rates rose in adults under 55

The overall rate in young adults rose from 33.90 to 62.18 cases per 100,000 people per year between 1993-94 and 2020, the clinical news site Patient Care Online reported from the paper. Among adults 55 and older the trend ran the other way, with rates declining from 618.78 to 453.04 cases per 100,000.

Group	1993-94	2020
Adults 20 to 54, all first strokes	33.90	62.18
Adults 20 to 54, strokes from a blocked vessel	23.8	47.3
Older adults, all first strokes	618.78	453.04

Rates are new cases per 100,000 people per year.

Strokes come in two main kinds. An ischemic stroke happens when a clot or narrowing blocks a blood vessel in the brain. A hemorrhagic stroke happens when a vessel bursts and bleeds. The rise in stroke incidence appeared driven by ischemic stroke, whose rate almost doubled, from 23.8 to 47.3 cases per 100,000 people per year. Bleeding strokes showed no comparable increase.

“While stroke has traditionally been considered a disease of older adults, our findings show that stroke is becoming increasingly common in younger adults,” said lead author Emily Fisher of the University of Cincinnati.

A smaller share of young stroke patients died within 30 days

One trend went the right way. There was a modest decline in the 30-day death rate among young adults, from 11.7% in 1993-94 to 9.4% in 2020. In the authors’ reading, the improvement was driven by intracerebral hemorrhage (27.5% in 1993/4 to 21.2% in 2020), which is bleeding inside the brain itself. For bleeding around the brain, called subarachnoid hemorrhage, the share who died fell by more, from 27.9% to 18.6%, but the authors could not rule out chance for that change, as can happen when cases are few.

Co-author David Robinson read it as a sign of better hospital care. “Our study might provide evidence that we have gotten better at treating people who have hemorrhagic strokes and helping them survive, which is encouraging,” Robinson told Fox News.

Survival is not recovery. More strokes and better survival mean more people living with the effects for decades. A review of stroke in young adults in The Lancet Neurology put it plainly: these patients have a long life expectancy after stroke. “This has major implications, since young people who develop disability from a stroke may no longer be able to work or provide for their families,” Robinson said.

What changed among young adults who had strokes

The team also looked at the medical histories of the young patients in each period. Hypertension, diabetes, atrial fibrillation, and substance use were more common over time. Hypertension is high blood pressure. Atrial fibrillation is an irregular heartbeat that lets clots form in the heart.

The largest shift was in drug use. Documented substance use rose from 4.6% to 40.2% in the study period, primarily marijuana, Fox News reported. Robinson was careful about what that means. “It’s hard to say whether this is responsible for any of the rise in stroke; there is a relationship between marijuana use and stroke, but most of the evidence is with heavier use,” Robinson said. Some of the increase may simply be that doctors now ask, and patients now answer, more readily.

The authors’ own summary is that the rise in strokes coincides with a rise in both traditional vascular risk factors and substance use. Vascular means relating to blood vessels. Coincides is the operative word.

A cardiologist who was not involved in the study said the direction is what matters. The concern, said Jason Gluck of AtlantiCare in New Jersey, is that “stroke rates are moving in the wrong direction for the younger population”. On the reasons, Gluck pointed to the same conditions that drive stroke later in life. “Vascular disease doesn’t suddenly begin when you’re 65; it develops over time,” he said.

Where this fits: stroke trends in young adults elsewhere

The Cincinnati result is not isolated, and the best comparison comes from England. The Oxford Vascular Study uses a similar method, counting and verifying every event in a fixed population. It was a prospective population-based incidence study conducted from April 2002 to March 2018, meaning it set out in advance to count every new case in a defined population. Between the first and second halves of that period, stroke became 67% more frequent in people younger than 55 and 15% less frequent in people 55 and older.

Two details from Oxford complicate the simple explanation. First, the rise in young people was seen for stroke and mini-stroke but not for myocardial infarction and other major vascular events, where myocardial infarction means a heart attack. If worsening blood pressure, weight and diabetes were the whole story, heart attacks in the young would be expected to rise too. Second, the increase was still seen in individuals without these risk factors. The increase was greatest in professional/managerial occupations.

The Oxford authors did not claim to know why. Given the absence of the divergence for other vascular events, they wrote, further research is needed to understand the causes of this difference. The divergence they mean is the split between young and old, which heart attacks and other blood-vessel events did not show.

National data from the United States had already pointed the same way. Analysts at the Centers for Disease Control and Prevention examined hospital admissions from 1995 to 2012. Admission rates for ischemic stroke rose in adults aged 18 to 54, and they have almost doubled for men aged 18 to 34 and 35 to 44 years since 1995-1996, the analysts wrote at the time. As in Cincinnati, hospitalization rates for intracerebral hemorrhage and subarachnoid hemorrhage remained stable. And as in Cincinnati, the prevalence of stroke risk factors among those hospitalized for acute ischemic stroke continued to increase.

That paper named a doubt that hangs over all such trends. There has been concern that this reflected improved diagnosis through an increased use of imaging rather than representing a real increase, its authors wrote. Brain scanning has become far more sensitive since the 1990s, and a small stroke that once went unnamed is now more likely to be found.

A national telephone survey carries the picture forward. From 2011-2013 to 2020-2022, overall self-reported stroke prevalence increased by 7.8% nationwide, prevalence meaning the share of people who have ever had a stroke. Increases occurred among adults aged 18-64 years, and not among those 65 and over. Among adults aged 18 to 44 the increase was 14.6%, from a low base: 0.9% of that age group reported ever having had a stroke.

Limits of the young stroke study

It cannot say why. The study’s main limitation, as Robinson described it, is that it has no comparable information on people who did not have a stroke. “We can’t say for sure how many of the stroke risk factors are changing in people without stroke in our region,” Robinson said. Without that, a rise in high blood pressure among stroke patients cannot be turned into an estimate of how many strokes it accounts for.

Detection changed over the period. Fox News reported that the results may have been affected by changes in medical documentation and diagnostic methods over the nearly three decades, including wider use of brain scanning. The pattern argues against that being the whole explanation, since better scanning would be expected to raise the count in older adults too, and theirs fell.

It is one region. The study draws on five counties, which its authors describe as broadly similar to the country as a whole in race, education and income. It counts only strokes that reached a hospital.

The last period was 2020, the first year of the pandemic, when hospital attendance was disrupted, which may have affected that year’s count.

Younger patients are also thinly covered by treatment research. They are usually not included in trials, the same review noted, so what works best for them is less certain than for older patients.

In one closely watched region of the United States, first strokes in adults aged 20 to 54 nearly doubled between 1993 and 2020 while falling in their elders, and the study that documents it has no data that could say what is driving the rise.