The role of sociodemographic factors play in the distance from the nearest stroke hospital may be more apparent in non-urban areas, a study showed.
Disparities in proximity to certified stroke centers were more prominent in non-urban areas than urban areas defined by the U.S. Census Bureau:
- Census tracts with a greater proportion of people age 65 and older were associated with increased median distance to a center in non-urban areas (0.51 km [0.32 miles] per 1% increase in representation) but not in urban areas
- Travel distance increased with higher representation of American Indians in non-urban and urban tracts alike, though the increase was more drastic in the former (1.06 vs 0.10 km [0.66 vs 0.06 miles] per 1% increase)
- Similarly, median distances increased more in non-urban census tracts with more uninsured populations (0.27 vs 0.02 km [0.17 vs 0.01 miles] per 1% increase)
“These trends ostensibly reflect the relatively greater geographic dispersion of the non-urban population, which has the effect of magnifying demographic disparities in proximity to certified stroke care,” said study authors Akash Kansagra, MD, MS, of Washington University School of Medicine in Saint Louis, and colleagues.
The concern is that disparities in proximity to certified stroke care may translate into disparities in clinical outcomes for disadvantaged populations, though this was not addressed by the paper, the researchers noted in their study online in Stroke.
Kansagra’s group explained that the average non-urban tract was about five to six times farther from a stroke hospital compared with the average urban tract (travel distance 30.2 vs 6.2 km [18.76 vs 3.85 miles]).
“Although our analysis shows that demographic disparities are more pronounced in non-urban than urban areas, we must highlight that urbanicity itself is perhaps the largest source of disparity in proximity to stroke care,” the investigators said.
“To reduce this location-based penalty, certifying bodies must continue to encourage development and certification of stroke centers in non-urban areas and emphasize return of investment in terms of health benefits to citizens rather than financial benefits to hospitals,” the team suggested.
State legislatures can also help, the researchers said, by developing more integrated and coordinated systems of care that can more rapidly triage and transfer non-urban stroke patients.
“However, it is also important to understand that the geographic accessibility of stroke hospitals is only one piece of a much larger series of issues,” commented Michael Mullen, MD, MS, of the University of Pennsylvania in Philadelphia, and Olajide Williams, MD, MS, of Columbia University and New York-Presbyterian Hospital in New York City.
“For example, differences in stroke recognition, emergency medical services utilization, and care-seeking behavior related to social determinants of health may vary by race/ethnicity and lead to prehospital delays independent of geographic distance to the nearest stroke center,” the duo wrote in an accompanying editorial.
For the cross-sectional study, Kansagra and co-authors used population data from the U.S. Census Bureau’s 2014-2018 American Community Survey. Each census tract was linked to a closest certified stroke hospital that provided intravenous thrombolysis.
The researchers analyzed 99% of the census tracts in the contiguous U.S., covering 2,388 stroke centers and more than 316 million people. Nearly 70% of tracts were classified as urban. Excluded tracts were the 1% that had a population of zero.
Notably, each $10,000 increase in median income was associated with a decrease in median travel distance of 5.04 km (3.13 miles) in non-urban tracts, but an increase of 0.17 km (0.11 miles) in urban tracts.
“Explanations for piecewise trends such as these include not only the nonuniform distribution of demographic subgroups, such as concentration of higher income groups in suburban areas on the periphery of urban areas, but also differences in infrastructure, including more numerous hospitals and higher density road networks in urban areas,” Kansagra and co-authors wrote.
One limitation of the study, they said, was that the group had to compile their list of stroke hospitals manually, potentially inadvertently leaving out some centers from their analysis. Additionally, actual travel time to the nearest stroke center may be a more clinically relevant metric, the team acknowledged.
“It is uncertain how much distance is required to make a clinically meaningful impact,” Mullen and Williams said. “Furthermore, the impact of distance, in terms of delaying time to hospital arrival, may vary across regions based on traffic patterns.”
Other caveats to the study, the editorialists said, include the very broad definition of “urban” — with no distinction between major urban, minor urban, and suburban areas — and the pooling of primary and comprehensive stroke centers together.
“Notwithstanding, addressing the barriers posed by physical distance to stroke centers as highlighted in this study is a necessary and important pursuit, although their intersection with social determinants of health — the major overarching drivers of stroke disparities — will be key in the quest for health equity,” Mullen and Williams concluded.
The study was supported by an award from the National Center for Advancing Translational Science.
Kansagra reported personal fees from Microvention, Penumbra, and iSchemaView.
Mullen disclosed prior Agency for Healthcare Research and Quality funding for similar research; Williams reported no conflicts.