And a disproportionate share of the bill will be for African-American and Latino stroke patients, because of their tendency to suffer strokes at younger ages and get poorer-quality preventive care than others. In fact, stroke-related costs among people under age 65 account for about half of the predicted total, which includes lost wages.

The study, published August 16 in the online version of the journal Neurology and funded by the National Institutes of Health, highlights the importance of efforts to prevent future strokes in all ethnic groups, but especially in young and middle-aged African Americans and Latinos, says lead author Devin Brown, M.D., M.S., an assistant professor in the U-M Medical School Department of Neurology and a member of the U-M Stroke Program.

"Doing the right thing now ultimately could be cost-saving in the future, but we have a long way to go before all Americans receive adequate stroke prevention and emergency stroke care," she says. "If our society is not going to do it for the right reasons, perhaps we can do it because it's going to be obscenely expensive."

Brown and her colleagues say their $2.2 trillion estimate is extremely conservative, because it is based on current rates of the conditions that put people at higher risk of stroke -- such as diabetes, cardiovascular disease and obesity. Such conditions are projected to become even more common in the future.

The $2.2 trillion estimate includes the cost of everything from ambulances and hospital stays to medications, nursing home care, at-home care and doctor's visits. They also include lost earnings for stroke survivors under age 65, based on current median salaries for each ethnic group. Earnings of those over 65 weren't included.

What can Americans do to decrease this looming bill? No matter what their age or ethnicity, individuals can cut their own risk of a future stroke by quitting smoking, losing weight, eating healthily, exercising, and keeping their blood pressure, cholesterol levels and any heart-rhythm problems under control, says Brown.

Meanwhile, doctors and hospitals can do a better job of providing preventive care and screening to patients with high blood pressure, clogged arteries and heart-rhythm problems. And, they can improve their use of a post-stroke drug called tPA.

The study projects the cost of ischemic strokes, which account for about 88 percent of all strokes. They occur when a clot or a clogged blood vessel blocks the flow of blood to all or part of the brain.

The interruption of blood flow causes sudden, severe symptoms that may include dizziness, numbness, paralysis of the face, arms or legs, problems with speaking or swallowing, confused thinking, loss of vision, and fainting. If the stroke isn't diagnosed and treated quickly and properly, death can occur within minutes or hours, or the person may survive but be left with permanent disabilities caused by the death of large numbers of brain cells. Patients need to call 911 for stroke symptoms to increase their chances of doing well after the stroke.

Treatment with tPA in the first three hours after an ischemic stroke begins can restore blood flow to the brain, preventing damage and reducing the cost of the patient's future care. But only about three percent of ischemic stroke patients who could receive tPA actually do. Delays in recognizing stroke and getting to an emergency room cause many patients to arrive too late for tPA. Hospitals' and doctors' ability to diagnose stroke quickly and willingness to deliver the drug also gets in the way; tPA carries a risk of fatal bleeding if given to the wrong patient.

Stroke is the third-leading cause of death in the U.S. and a leading cause of serious disability. About 700,000 Americans suffer a stroke each year, and 157,000 of them die.

The new study is based in part on data from two major stroke studies performed in areas of Texas and New York with higher-than-average numbers of Latino residents, so as to get an accurate picture of stroke incidence and care in the largest minority populations as well as among African Americans and non-Hispanic whites. They are the BASIC study and the NOMASS study.

Those data were combined with national census data and population projections and average stroke-care costs. Lost wages for the 47 percent of under-65 stroke survivors who don't return to work were included, but lost productivity for the 53 percent who do return to work were not.

"Because members of the two largest minority groups have their strokes earlier than non-Hispanic whites, the impact of lost earnings is greater than non-Hispanic whites per capita," says Brown.

On average, 2 percent of non-Latino whites under age 65 have had a stroke, while 9 percent of those over age 65 have had one. Those rates are higher among minorities: 2.3 percent and 10 percent for Latinos, and 4.8 percent and 10 percent for African-Americans. Differences in risk factors, genetics and care may account for much of this difference.

Latinos, currently the largest minority group in the U.S. with 13 percent of the population, are expected to make up 25 percent of the population by the year 2050. African-Americans currently make up 12 percent of the national population and will be 14 percent by 2050. Both groups have a median age of about 10 years younger than the median for whites, and both are expected to achieve higher socioeconomic status as time goes on.

In all, the study finds that the total direct and indirect costs of stroke in the next 45 years will be $1.52 trillion for non-Hispanic whites, $313 billion for Latinos, and $379 billion for African Americans. But on a per-capita basis across the whole population, a white stroke victim's costs will average just under $16,000, while the cost for each Latino stroke patient will be just over $17,000 and the cost for each African American stroke patient will be nearly $26,000.

"We need to examine stroke in African Americans and Latinos further, and strengthen efforts to improve stroke prevention and acute stroke treatment for all patients, but especially these two groups," says senior author Lewis Morgenstern, M.D., professor of neurology, neurosurgery and emergency medicine at U-M and director of the U-M Stroke Program.

umich