By Andrew M. Seaman
NEW YORK (Reuters Health) - The number of Americans having strokes and the number dying following strokes decreased over the past 20 years, according to a new study.
The declines in strokes and improvements in survival were similar between blacks, whites, men and women, according to the researchers.
“Stroke is still the fourth leading cause of death and the leading cause of disability in the U.S. but we’re doing better,” said Dr. Josef Coresh, the study’s senior author from the Johns Hopkins Bloomberg School of Public Health in Baltimore.
More than 795,000 people in the U.S. have a stroke each year, according to the Centers for Disease Control and Prevention, and about 130,000 die as a result.
The vast majority of strokes are ischemic strokes, which occur when blood flow to the brain is blocked. About 10 percent of strokes, known as hemorrhagic stokes, are caused by leaking blood vessels.
Coresh and his colleagues write in JAMA, the journal of the American Medical Association, that some studies have reported a decline in stroke rates.
Whether that decline has been consistent among people of all races and among both men and women is still up for debate, however.
For example, some studies from the U.S. and UK found that strokes decreased among whites but not blacks, who are already known to be at greater risk of stroke than whites.
To learn more, the researchers analyzed data from a long-term study of 15,792 people in four areas of the U.S. The participants were between 45 and 64 years old when they entered the study between 1987 and 1989.
The authors restricted the current analysis to 14,357 people who had not had a stroke when they entered the study. They found 1,051 participants had a stroke by 2011 and 58 percent of those people died during the study period.
Over a given 10-year period, the stroke rate decreased by about one stroke per 1,000 people per year. That drop was similar between black and white participants, and between men and women.
Coresh noted that blacks were still at a greater risk for strokes than whites, because they had a higher rate of strokes to begin with.
“I think it’s very good that we’re seeing decreases among African Americans as well because there is a concern of health disparities,” Coresh said.
When the researchers divided participants by age, they found stroke rates only decreased among those ages 65 and older, however.
The chance of dying after having a stroke also fell during the study. Over a 10-year period, the number of deaths per 100 strokes dropped by eight. That decrease was particularly prevalent among the youngest study participants and was similar for both sexes and races.
Coresh said the decline in strokes and improvement in survival may be attributable to better control of risk factors - particularly high blood pressure, also known as hypertension - as well as increased smoking cessation and diabetes control.
“I think we’ve been working on hypertension awareness, treatment and control for 40 years now,” he said. “Largely it’s a story of success but as (with) many things in health it’s never done. We need to keep doing better and better.”
In an editorial accompanying the new study, Drs. Ralph Sacco and Chuanhui Dong from the University of Miami Miller School of Medicine’s Department of Neurology write that there is still considerable work to be done to lower stroke rates in the U.S.
“Greater improvements in brain health, especially with controllable risk factors such as diet, exercise, smoking, and obesity, among younger segments of the population are required to reduce the risk of stroke and enhance the chance of successful cognitive aging for all adults,” they write.