Stroke rates vary sharply by race, region

FORT LAUDERDALE, Fla. Feb. 14 – Southern black men appear to have the highest risk of stroke, according to studies presented today at the American Stroke Association’s 26th International Stroke Conference. The American Stroke Association is a division of the American Heart Association.

Researchers in three separate studies on stroke-related demographics found strong regional and racial variations in stroke risk, as well as in patterns of care and quality of outcomes.

“Generally, if you’re a non-Caucasian male living in some parts of the deep South, your risk of stroke is among the highest in the country,” says George Howard, Dr.P.H., chair of the department of biostatistics at the University of Alabama, Birmingham. “On the other hand, if you’re a white woman living in Manhattan, your relative age-adjusted risk could be considered among the lowest.” In a study analyzing gender, racial and geographic patterns of stroke mortality during the past 30 years, Howard’s group found a general nationwide decline in stroke deaths and striking changes in stroke prevalence and rates of decline. They also noticed huge regional differences.

Alabama and Mississippi, for example, are falling out of the so-called “Stroke Belt” that has traditionally extended across the Southeast, because the number of stroke deaths in these states has decreased sharply and continues to do so. But the stroke rates remain high in certain areas of Arkansas, Tennessee, Georgia and South Carolina.

These dramatic differences were clearly shown when researchers examined the 50 counties with the lowest stroke rates and the 50 counties with the highest. The southern tips of Florida and Texas, one county in southern New Mexico and, surprisingly, the high-stress New York metropolitan area had the lowest stroke rates in the country, Howard notes. Yet for reasons not clearly understood, certain counties in Oregon and Washington,- along with one county in northern Wyoming, had some of the nation’s highest rates.

“Rates within the same state can vary tremendously,” Howard notes. “South Florida is very low, for instance, while North Florida is high. It’s where we find clusters of counties with exceptionally high rates that we’re concerned.”

South Florida, South Texas and New York City also show some of the most pronounced declines in stroke deaths, while the amount of decline is generally smallest in the nation’s sparsely settled northwestern quadrant.

“The death rate from stroke is falling much faster among blacks than whites, although the rate for blacks is still higher than the rate for whites, which seems to have hit a plateau,” says Howard.

Researchers can only speculate about the underlying causes of these patterns. “Right now, it’s a major mystery,” Howard says. “The next step is to try to find out why all this is happening.”

Meanwhile, a study of nearly 1,200 patients at 42 U.S. academic hospitals also showed significant racial and regional variations in the use of thrombolytic (clot-busting) therapy with the drug tPA, which can minimize permanent disability if given promptly after the onset of stroke symptoms.

“The rate of thrombolytic use was lowest in the South, where only 1.2 percent of stroke patients received the therapy, and highest in the Midwest, with 9.5 percent receiving it,” says lead author David C. Tong, M.D., associate director of the Stanford Stroke Center in Palo Alto, Calif. “Our analysis also revealed that Caucasians had a significantly greater probability of treatment with tPA than non-Caucasians.

“It has been reported that non-Caucasians have less access to health care for many medical conditions compared with Caucasians,” Tong says, “but whether that’s the entire reason in this case isn’t known.”

The multi-center study showed conclusively, however, that (1) not all those suffering ischemic stroke (strokes caused by blood clots) are treated equally with the only approved therapy for lessening the debilitating effects of stroke and (2) the use of tPA remains far too low overall.

“Not enough stroke patients are receiving thrombolytic therapy for a variety of reasons,” Tong says. “One factor is the time window -- three hours or less after symptoms begin for tPA treatment -- but this isn’t the entire explanation. To expand the use of tPA, the general level of stroke awareness needs to be raised, both among people at risk and their caregivers as well as among health care professionals. We also need to figure out why specific groups are apparently not receiving this effective treatment.”

Researchers in a third study involving more than 55,000 patients in VA medical centers also found clear regional variations in outcomes and patterns of care following ischemic stroke.

“We found lower stroke death rates after hospital release in the Northeast and West, compared to the South and Midwest,” says Linda S. Williams, M.D., a researcher at Roudebush VA Medical Center in Indianapolis and assistant professor of neurology at the Indiana University School of Medicine. “This was true despite the fact that those in the Northeast were sicker, had longer average hospital stays and higher in-hospital mortality.”

The post-discharge death rate was 18 percent lower in the Northeast and 9 percent lower in the West compared to the South.

A key factor in the better survival rates for those in the Northeast and West, the study found, was that these individuals more frequently saw neurologists or primary care physicians within 60 days and within one year after leaving the hospital. Stroke survivors in the Northeast and West were approximately 33 percent more likely than those in the Midwest and South to see a neurologist or primary care physician within 60 days after a stroke.

“Our conclusion is that the death rate after stroke is lower in regions where more patients get follow-up care,” Williams explains. “We still have much to learn about what types of post-stroke care are most beneficial. Meanwhile, our message to the public is to call 9-1-1 quickly if someone is having a stroke and to continue to see a physician for preventive treatment and risk factor modification during the post-stroke period.”

CONTACT:
For information Feb. 14 –16, contact Bridgette McNeill or Carole Bullock
Greater Fort Lauderdale Convention Center
(954) 765-5484

Abstracts 25, P125, P198

In addition to Howard, researchers in the study of county-by-county stroke rates include Charles R. Katholi, Ph.D.; Virginia J. Howard, M.S.P.H.; Madan K. Oli, Ph.D.; and Sara Huston, Ph.D. Working with Tong on the thrombolytic therapy study was David Grosvenor, M.P.H. Williams’ research associates in the VA study include Morris Weinberger, Ph.D.; George Eckert, M.S.; Gilbert J. L’Italien, Ph.D.; and Pablo Lapuerta, M.D.

NR01–1237 (StrokeConf/Howard/Tong/Williams)