Chen Lin, M.D.A recent study authored by UAB researchers in the departments of Neurology, Medicine, and Epidemiology analyzed a decade of data to reveal that lack of access to stroke-related clinical trials may limit access to innovative treatments in geographic regions with high stroke burdens. Stroke is a leading cause of death and disability, affecting more than 795,000 people annually, with age-adjusted mortality rates varying widely by state.

Published in Neurology, the study, “Geographic Disparities in Stroke Clinical Trials Across the United States: A Decade of Data (2010-2020),” is co-authored by Chaitali Dagli, MPH, of the UAB Department of Epidemiology, Evan Liu, B.S., and Yihan Zhong, B.S., both of the UAB Department of Medicine and both students in the Heersink School of Medicine, and Chen Lin, M.D., Ph.D., of the UAB Department of Neurology, along with researchers from Stanford University School of Medicine and Capstone College of Nursing.

According to Lin, whose research focuses on stroke recovery and rehabilitation, previous studies at UAB, like the REGARDS study, have looked at disparities regarding stroke care. This prompted him and his lab team to investigate whether there was a similar pattern in stroke clinical trial research across the United States, for which data has previously been limited.

“That is one of the main reasons why we conducted this study, to look at whether we see significant differences in access to stroke clinical trials in regions that see a significantly high burden of cerebral vascular disease and mortality, like we do here in the Southeast,” Lin said.

The research team looked at public data available on ClinicalTrials.gov spanning a decade, from 2010 to 2020, and searched for all completed studies during that time period related to stroke or cerebrovascular disease. The team also looked at data from the Centers for Disease Control and Prevention to consider stroke mortality and hospitalizations within a similar time period.

“We use that to get what we call a relative study frequency, an RSF value, which is basically the distribution of studies relative to the stroke burden,” Lin said.

“Stroke burden,” Lin explained, is defined by hospitalization rates among Medicare beneficiaries and the number of stroke deaths related to the age-adjusted stroke death rate. The data was then mapped with states categorized into four quartiles depending on their RSF values, with the highest quartiles representing the highest disparities.

A breakdown of findings:

• 649 clinical trials were completed across 40 states.
• 10 states had no registered trials.
• Mississippi and Louisiana had the highest stroke hospitalizations with minimal research activity.
• California and New York had greater clinical trial availability to address the stroke burden.
• In general, stroke trial availability is disproportionately low in high burden regions, particularly the Southeast and Midwestern regions.

“Many of the states in the Southeast were in the highest quartile, including Mississippi and Louisiana,” Lin echoed. “And what we typically consider high resource states, like California and New York, were in the lowest quartile, so they had some of the lowest disparities. So that wasn't as surprising.”

What was interesting, according to Lin, was the fact that some Southeastern states like Alabama and Georgia appeared in the higher quartiles. Lin credited UAB and its status as a StrokeBelt StrokeNet Center as to why it potentially reflected a lower number of disparities in the study.

“Alabama is classically high in stroke mortality and hospitalizations, but because we have high access to clinical trials here in stroke, we actually did quite well,” Lin said.

States like Texas, North Carolina, Florida, Illinois, Pennsylvania, and Ohio also appeared in the two lower quartiles, reflecting more trials relative to stroke burden. States such as Arkansas and Iowa also showed a higher stroke burden than research availability.

Looking toward the future of stroke clinical trials

For those states with low clinical trial access and high stroke burden, one goal is that new technology and telehealth can play a role in expanding access to trials.

“Since COVID, we’ve seen the spread of telehealth and new technologies,” Lin said. “So hopefully, when we or another group looks at this data again in the 2020-2030 decade, they can see some of those implementations of new technology regarding telehealth and implementing more clinical trial access to rural hospitals.”

But while telehealth can be a tool to facilitate trials, it is not the only key to expanding access, according to Lin.

“New technology can definitely play a role, but I think a lot of that also has to be intentional and purposeful,” Lin said. “It’s not something that exists for the sake of existing. You must be in the right situation for these hospitals and these research institutions to allow patients to have access to these clinical trials –to bring more trials to the states that need them for the patients that need them.”