Location makes a significant difference in stoke treatment in the USA


A new map of emergency stroke care in the USA illustrates the patchwork system in place for delivering the most effective treatment. In the journal Stroke, University of Michigan Medical School researchers report the results of a study that for the first time shows wide geographic variation in use of “clotbuster” treatments for stroke.

Only 4.2% of more than 844,000 stroke victims received the tPA drug or another urgent stroke treatment, the study found. If given in the first hours after a stroke, tPA and other treatments can restore blood flow in the brain and prevent the damage that causes stroke-related disability and drives up the long-term cost of caring for stroke survivors.

When the researchers looked at how tPA was used—or not used—in Medicare participants who had strokes in each of the USA’s 3,436 hospital markets between 2007 and 2010, deep divides emerged. In one-fifth of these regions, no patients received tPA.

Meanwhile, in some places, as many as 14% of stroke patients received tPA through an intravenous line, or a intrarterial treatment that involved tPA or another strategy.

“These results scream that a major opportunity exists to improve emergency stroke care, if only we can understand how these differences arise and how to eliminate them,” says James Burke, the study’s senior author and an assistant professor in neurology at the University of Michigan and the VA Ann Arbor Healthcare System. “If we had a perfect system in place nationwide, which delivered treatment at the highest rates seen in this study, thousands of patients could be spared disability.”

When the researchers grouped the regions from best-performing to poorest-performing and looked at them closely, they found more surprises. In the top fifth, an average of 9% of patients received clot-busting treatment, while in the bottom fifth, no patients received it.

Even after they adjusted for the number of strokes that each region reported during the four years, there was a wide gap in the use of emergency stroke treatment. In addition, older patients, women, and members of racial and ethnic minority groups were less likely to receive tPA regardless of where they lived.

While patients were somewhat more likely to receive tPA if they had their strokes in regions where hospitals were certified as primary stroke centres, which can deliver tPA around the clock, or where ambulance companies had a policy of driving stroke patients further to get to a stroke centre, those factors did not make a major difference.

“We can clearly do much better, but existing policy solutions are only going to get us so far,” says Burke. “In our findings, we do see positive results from primary stroke centre designation and ambulance bypass, but we are talking about a complex mix of hospital, EMS, and individual response to stroke. We need to understand better what the areas with the highest rates of use are doing differently.”

At the time of the study’s data, comprehensive stroke centre designation, which indicates the most advanced level of stroke care including intrarterial tPA, was not yet in use.

The researchers calculated that if all regions achieved the same rates of tPA use as the Stanford region, more than 92,800 people would get treated, and 8,078 people would survive their stroke disability-free. Even if all regions doubled their current tPA use, 7,206 people would be spared disability.

Variation in tPA use was associated with lower average levels of education and income, and higher unemployment, in hospital service areas, and use was slightly higher across all densely populated areas compared with more sparsely populated areas. The top 20 areas for tPA use are scattered across the country, in urban and rural areas, rich and poor.

“By studying communities that treated a lot of stroke patients, we may learn how best to help low-performing communities treat more acute stroke patients in their community,” says lead author Lesli Skolarus, a stroke neurologist and assistant professor at the University of Michigan.