In a recent study from the USA now published in the journal Neurology, Black people consistently had a higher rate of stroke than white people over a 22-year period. The same study also found that the average age of Black people experiencing stroke was nearly 10 years younger than that of white people—an inequity that grew over time.
“We found that the rate of stroke is decreasing over time in both Black and white people—a very encouraging trend for US prevention efforts,” said study author Tracy Madsen (Brown University, Providence, USA). “But, there was an inequity from the beginning of the study, with the rate of stroke always being higher for Black people than their white counterparts. The disparity did not decrease in 22 years, especially among younger and middle-aged adults.”
Researchers evaluated stroke trends over time using data from hospitals in southern Ohio and northern Kentucky from 1993 to 2015. Stroke cases were recorded across a full year every five years—about 1,950 cases per year for a total of 9,728. Using US census data, the researchers were able to calculate stroke incidence rates per 100,000 people.
The overall rate of stroke decreased from 230 cases per 100,000 people in 1993 to 188 cases per 100,000 people in 2015. For Black people, the rates went down from 349 to 311 and, for white people, they declined from 215 to 170.
The rate of stroke among Black people continued to be 50–80% higher than the rate among white people across the 22 years, even after adjusting for age and sex—a disparity that was particularly stark in younger and middle-aged Black adults. The disparity shrank in older age groups, with researchers saying this difference may be due to varying survival rates between Black and white people.
While the rate of stroke was decreasing, the study found that strokes were occurring at younger ages over time, and that this change was larger in Black people, exacerbating an existing disparity. Black people experienced stroke at an average age of 66 years at the beginning of the study compared to 62 years by the end of the study. For white people, the average age was 72 years at the beginning of the study and 71 years two decades later.
“These disparities present a major ongoing public health concern,” Madsen added. “More work is clearly needed to address systemic and policy problems, as well as factors at the provider and patient levels. These findings are a clear, urgent call for concrete efforts to build more equitable means of stroke prevention and care.”
Madsen noted that a limitation of the study—supported by the National Institute of Neurological Disorders and Stroke—was that, while race was the primary focus of the study, the key social factors that contribute to racial inequities like systemic racism and access to preventative care were not measured.
