Ethnic inequalities in stroke explained by differences in stroke risk factors
King's College London
Stroke risk is primarily linked to differences in traditional stroke risk factors, like diabetes and high blood pressure, rather than ethnicity, according to findings from a new South London study conducted at King’s College London.
The research found that while Asian and Black individuals were more likely to have diabetes or hypertension than White individuals, the likelihood of someone having a stroke once they had these conditions was similar across ethnic groups.
Although previous research has consistently shown higher rates of stroke in some ethnic groups and has identified hypertension and diabetes as important contributors to these inequalities, the role of ethnicity on the risk of stroke has remained controversial.
The King’s College London study – funded by King’s Health Partners, Guy's & St Thomas's Charity and the National Institute for Health and Care Research (NIHR) – set out to examine this relationship in more detail by looking separately at the development of cardiometabolic risk factors and the subsequent progression from these conditions to stroke.
Published in BMC Public Health, the study analysed primary care electronic records from more than 650,000 people in South London, collected from 41 GP practices in Lambeth between 2005 and 2021. The study included patients of Asian, Black and White ethnicity and examined three major risk factors for stroke: hypertension (high blood pressure), diabetes and hypercholesterolaemia (high levels of cholesterol in the blood).
To study the relationship between ethnicity, the cardiometabolic risk factors and stroke, the researchers used a modelling technique called a ‘multistate analysis.’
This technique allows researchers to analyse how an individual moves through different health events or ‘states’ over time – in this case moving from having no risk factors, to having one of the risk factors, and then on to having a stroke. Using this method, the researchers calculated the probability of individuals moving from one state to the next.
As the researchers expected, the occurrence of stroke risk factors was higher in Black and Asian patients than in White patients. Ethnicity was significantly associated with the probability of developing all three stroke risk factors, especially diabetes and hypertension. Compared with White patients, Black patients were around twice as likely to develop hypertension and more than twice as likely to develop diabetes. Asian patients were about 50% more likely to get hypertension and were three times as likely to get diabetes than White patients.
However, when the researchers looked at the transition from stroke risk factor to stroke itself, these patterns disappeared. Among patients with hypertension or diabetes, Black and Asian ethnicity did not confer a higher probability of progressing to stroke than that observed in White patients with the same conditions. The authors say this finding confirms that ethnic inequalities in stroke incidence are primarily associated with the cardiometabolic risk factors.
Dr Marc Delord, Research Fellow in Medical Statistics at King’s College London, said: “We know that stroke occurs more frequently in some ethnic groups. Our study explains that these inequalities are attributable to traditional modifiable cardio-metabolic risk factors only: Although Black and Asian patients were more likely to develop these risk factors, particularly hypertension and diabetes, once these conditions are present, their subsequent probability of stroke was not higher than that of White patients.
“Our findings reinforce the need for prevention, detection and management strategies that account for the higher burden of these modifiable risk factors observed in Black and Asian populations, including culturally tailored lifestyle interventions, to help reduce inequalities in stroke risk.”
Professor Abdel Douiri, Professor of Medical Statistics and Clinical Trials at King’s College London and co-author of the paper, added: “These findings underscore a clear message: reducing ethnic disparities in stroke requires addressing the underlying inequalities in the prevention, early detection, and effective management of hypertension and diabetes, which disproportionately affect Black and Asian communities.”
Hypercholesterolaemia did not fit the same pattern as the other risk factors. Among Black patients with hypercholesterolaemia, the study identified a slight increase in the subsequent likelihood of stroke compared with White patients. The authors say this finding needs further investigation.
Previous research recently published in BMC Medicine from the team in the same study population found that Black patients with hypercholesterolaemia were less likely to receive statin treatment. Although data on medication prescribing were not included in the current study, the researchers would like to investigate whether the reduced prescribing of statins could help to explain the increased occurrence of stroke observed in this population.
Journal
BMC Public Health
University of Cincinnati study finds patients participating in stroke research value forming relationships and visualizing real-world impact
Research published in the journal Health Expectations
New University of Cincinnati research found participants in stroke rehabilitation research prefer an approach that prioritizes shared decision-making, peer relationships and a focus on what they can accomplish over one that emphasizes their deficits.
The research, led by corresponding author Sarah Schwab-Farrell, PhD, was recently published in the journal Health Expectations.
How did this research begin?
Schwab-Farrell specializes in physical therapy and experimental psychology. Her research has focused on carefully designed studies that collect data about how people with disability move, including capabilities of those who have had strokes.
While conducting studies over the past several years, she noticed participants seemed to not find the research as enjoyable or engaging.
“Participants found it interesting to be immersed in virtual reality or use motion capture, but they would leave not really feeling like they understood more about their disability or how the carefully controlled data we collected would practically help other people with disability,” said Schwab-Farrell, assistant professor in UC’s College of Allied Health Sciences.
Around the same time, Schwab-Farrell was engaging further in disability studies literature that seeks to prioritize the voices of people with disability.
“I gradually started to gain an understanding that if I really wanted to be an impactful disability researcher, I needed to not only study disability but also make sure that disabled voices were an active part of the research created,” she said. “The scientific impact and merit of a study matter in an academic context, but impactful research should also matter to the people whose lives are directly affected by the outcomes of research.”
Through this work, Schwab-Farrell identified that she had brought her research expertise to studies, but the pragmatic lived experience of people with disabilities had been missing.
What does the research look like?
To address this missing component, Schwab-Farrell and colleagues designed a two-year project focused on building a study from scratch with co-researchers who have had a stroke.
In the first-year discovery phase, the team conducted four iterative focus groups with five individuals who had participated in an average of eight prior stroke research studies at UC.
“We wanted to get a handle on what people with stroke value in research, their likes and dislikes,” Schwab-Farrell said. “It was really important that this group was able to draw on a wide variety of prior research experiences to share desired study features and so that a wide range of stroke-related disability was represented.”
What did the researchers find?
Schwab-Farrell said the most impactful finding from the focus groups for her was learning that participants value peer relationships and would like to see relationships more deeply integrated into study designs.
“After stroke, relationships change, and people with stroke build a new support network,” she said. “For those who are involved in research experiences, researchers become part of that support network.”
The participant experts also emphasized the value in being a fully informed participant, meaning they know potential study benefits, relevance and how this work could help other folks down the road.
“Further, individuals with stroke appreciated capacity-oriented studies, or studies that emphasize what people with stroke can do rather than focus exclusively on deficits,” Schwab-Farrell said. “I think it is important for researchers to address this and find ways that ‘success’ can occur in studies or ways that de-emphasize individual deficits.”
What are the next steps?
Schwab-Farrell and her team of academic and stroke community researchers are now using their first-year findings to design a physical or occupational therapy study that is meaningful and relevant to participants.
“We had our first co-design workshop last month, and our second workshop will occur later in October where we are going to determine our research question,” she said. “We already have some great ideas floating around, so I am excited to see what the group comes up with.”
On a larger scale, Schwab-Farrell said the findings can be applied to any stroke or disability researchers looking to make their studies more collaborative.
“Collaboration should be more than consultative and checking a box, but genuinely involve people with disability in all aspects of the study design/production, from the development of a research question all the way to dissemination/translation,” she said.
Journal
Health Expectations
Article Title
‘Some of Them Were Created by People Who Have Never Had a Stroke’: Understanding Desired Physical and Occupational Therapy Research Study Features for People With Chronic Stroke
Article Publication Date
8-Oct-2026
