Prevention is key to closing racial disparity gap in stroke

Few studies have examined whether the elevated stroke rate in blacks explains why there are more stroke deaths. The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study investigated why blacks and U.S. Southerners are more likely to die from stroke. They found the higher number of stroke deaths is due to a greater number of strokes occurring at younger ages among blacks.

At age 45, blacks were four times more likely to die of stroke than their white counterparts in this analysis. By age 85, there was no difference in stroke death rates among blacks and whites.

"The magnitude of public health burden of the racial disparity in stroke is staggering, with an estimated 22,384 "extra" stroke events i.e., above what would be expected relative to rates in whites occurring in blacks in 2014," said George Howard, Dr.P.H., study lead author and a professor of biostatistics at the University of Alabama at Birmingham School of Public Health. "With a life-long cost of stroke of $104,000 for each of the events, this black-white difference in stroke costs America more than $2.3 billion annually. Obviously, efforts that would even marginally reduce this burden would pay remarkable dividends for the U.S."

He blamed racial differences in the development and control of risk factors and encouraged more aggressive prevention efforts.

"We need to do more to focus on prevention and control of risk factors before they result in a stroke. Unfortunately, most of the research resources are focused on treating stroke patients and preventing recurrent stroke."

Researchers said prevention efforts addressing risk factors like high blood pressure and diabetes that are more common in African-Americans are at the root of the problem; and to reduce the disparity in stroke we must "go further upstream" to make inroads on racial differences in the traditional and non-traditional risk factors that lead to stroke.

Researchers analyzed data on 29,681 people selected at random from across the United States. Conducted between 2003 and 2007, REGARDS used a combination of mail and telephone interviews to assess risk factors, followed by regular in-home visits to collect other biological samples and measure blood pressure, height, and waist circumference.

The pattern of stroke mortality they found in their study data mirrors national data, where the black-to-white hazard ratio for dying from a stroke is about 4.0 at age 45 but falls to just 1.0 by age 85. The researchers found that the risk of having a stroke followed a remarkably similar pattern; however, there were no black-white differences in the risk of dying once a stroke occurred.