Though incidence is lower overall, Black adults suffer stroke at higher rates and younger ages.
An analysis of stroke trends found that although stroke rates have decreased overall, Black patients still have incidence rates 50 percent to 80 percent higher than white patients.
While the study did not examine other ethnic groups or the direct contributors to these trends, including the role of social determinants of health, researchers did investigate differences in stroke risk factors, says study author Tracy Madsen RES’12 F’14 ScM’14 PhD’21, MD, associate professor of emergency medicine and of epidemiology.
“Things like high blood pressure, diabetes, and whether or not someone smokes cigarettes are three of the most important stroke risk factors, and they are more prevalent in Black adults than white adults,” she says. “We were not able to measure or describe potential inequities in access to care for these conditions in the participants.”
The study, which was published in Neurology, focused on the populations of five counties in Ohio and Kentucky from 1993 to 2015. The researchers used data from the Greater Cincinnati/Northern Kentucky Stroke Study, which began in the early 1990s. The population of this region has been shown to represent the US in terms of race and socioeconomic conditions.
Although the overall incidence of stroke decreased among Black and white adults, substantial differences between both groups still exist. Researchers used more than 9,700 cases of stroke over the five study periods along with US Census data to calculate standardized incidence rates per 100,000 people. Across the study’s time period, incidence rates for white patients fell from 215 to 170, while rates for Black patients fell from 349 to 311.
Madsen says she was surprised to discover that stroke rates among Black adults had declined. However, she and her coauthors found some age-related concerns within the data.
“The age in which the [first]stroke occurred in this population went down over time, and by 2015 the difference between Black and white adults was almost 10 years,” Madsen says. “Essentially, Black adults are having strokes about 10 years younger.”
The inequities in stroke risks were highest in the younger and middle age groups, 20 to 54, which presents its own set of challenges.
“This is an age group that, as people are entering middle age, they may not be getting adequate screening or treatment,” Madsen says. “It points to another set of interventions that need to happen as a result of this study by focusing on stroke during middle age and not waiting until 60 or 70 before adequately controlling risk factors, especially in minoritized populations.”
Madsen says studies like this help increase awareness of disparities within the health care system. Initiatives at the community level—such as programs that increase access to care; primary care doctors, pharmacists, and providers who can help people obtain blood pressure medications; or even services that help with transportation or finances—may improve outcomes in Black adults.