There appears to be a reduction in the number of older adults who experience strokes and a similar reduction in the number of fatal strokes.
A recent study, published online in the journal of the American Academy of Neurology, identified declines in both ischemic stroke, which results from blockage of blood flow to the brain, and intracerebral hemorrhage, in which a blood vessel bursts within the brain. The study involved research conducted on the population of Denmark.
“Stroke is the leading cause of death and disability in the world,” said study author Henrik Toft Sorensen, MD, PhD, DMSc, a professor of clinical epidemiology at Aarhus University Hospital in Aarhus, Denmark. “Recent research on the incidence of stroke has been mixed, and some studies have reported an increase among young people. However, our research found no increase in stroke among young people, and it also found the incidence of stroke declining among older people, which is encouraging.”
Study researchers examined national health care registries in Denmark to identify all individuals in the country who had been hospitalized for a first-time stroke between 2005 and 2018. Identified were 8,680 younger adults between the ages of 18 and 49 who had had a stroke during that time, and 105,240 adults aged 50 and older.
With incidence rates calculated for both ischemic and hemorrhagic stroke as well as subjects’ ages, researchers found the incidence rate of stroke in those aged 49 and younger remained level over the duration of the study, with approximately 21 cases of ischemic stroke per 100,000 person-years at the beginning and end of the study. Person-years consider both the number of people in the study and the time each individual spent in the study. For intracerebral hemorrhage, the incidence rate in young people was about two cases per 100,000 person-years at the beginning and end of the study.
The study also determined that the incidence rates of stroke declined in those aged 50 and older over the course of the study, with 372 cases of ischemic stroke per 100,000 person-years at the outset of the study and 311 cases at the end. For intracerebral hemorrhage, there were 49 cases per 100,000 person-years at the outset of the study and 38 cases at the end. However, stroke rates in people in their 50s were stable, with the most decline in those over the age of 70. “The decrease we found may be associated with better treatment of stroke risk factors, such as hypertension and atrial fibrillation, as well as falling smoking rates in the population,” Sorensen said.
Researchers also calculated death rates by analyzing the number of people who died in the month following a stroke and found that rates declined in both younger and older people. For ischemic stroke, 2.3% of younger individuals died one month after stroke at the start of the study, compared with 0.1% at the end. Among older adults, 8.2% died one month after stroke at the outset of the study compared with 6.0% at the end. For intracerebral hemorrhage, rates among both younger and older subjects declined as well.
“The improvements we found in survival rates are consistent with improvements in stroke care,” Sorensen said. “We also examined stroke severity and found while mild strokes increased, the most severe cases declined. These changes could be related to improvements in stroke awareness in the general population as well as the care people receive for stroke, including in the ambulance and emergency department prior to hospitalization. Such care has led to faster and improved diagnostics, particularly regarding the mildest of cases.”
Although a number of conclusions can be drawn from the study, because it was conducted in Denmark, results may not necessarily apply to populations in other countries. However, acute stroke care in the United States has undergone significant technological and clinical advancements, enabling providers to reduce the extent of disabilities as well as the number of deaths resulting from strokes.