A "stroke atlas," published by the U.S. Centers for Disease Control and Prevention, details dramatic disparities in stroke death rates all the way down to the county level and for the five largest racial and ethnic groups in the United States.
It finds that blacks are 40 percent more likely to die of a stroke than whites and more than twice as likely as Hispanics. It also finds that a South Carolinian was nearly twice as likely to die from a brain attack as a New Yorker.
The publication is being hailed as a major tool in the fight to prevent stroke. "The atlas is likely to prove one of the most important documents in stroke prevention in many, many years," said Dr. Ed Thompson, deputy director of the CDC, at a telebriefing Thursday. "It provides a way to see, literally, where stroke occurs. It allows us to plan research, to make policy and to develop interventions."
Stroke is the third leading cause of death in the United States, behind heart disease and cancer. Every year, 165,000 people die from stroke and about 700,000 people suffer a new or recurrent stroke. It's also a major cause of long-term disability.
The disparities in stroke death rates revealed by the atlas were stark, both between ethnic and racial groups and from location to location.
The atlas compiled data for adults aged 35 and older for the years 1991 to 1998 in the five largest ethnic groups: blacks, American Indians and Alaska Natives, Asians and Pacific Islanders, Hispanics, and whites.
"Whereas the national stroke death rate was 121 deaths per 100,000 population, the states ranged from a low of 89 in New York to a high of 169 in South Carolina. This means that death rates were almost twice as high in some parts of the country compared to others," said Dr. Michele Casper, lead author of the research and an epidemiologist with the CDC's cardiovascular health branch.
Massachusetts, New Jersey, Florida, and Rhode Island were the other states with the lowest death rates, while Arkansas, Tennessee, North Carolina and Georgia joined South Carolina as the states with the highest rates.
County-level disparities were even greater, ranging from a low of 61 to a high of 241 deaths per 100,000 population, Casper said. Adults living in southern counties along the coastal plains and the Mississippi Delta region suffered the greatest stroke burden.
The lowest rates were found primarily in the southwest, the Great Plains region and the Northeast.
In terms of ethnic and racial differences, the atlas shows that blacks are 1.4 times more likely to die of a stroke than whites and more than twice as likely as Hispanics and Native Americans.
Blacks were also more likely to suffer a stroke at a younger age: Half of all stroke deaths in this group occurred in people younger than 75, compared with 45 percent for Asians and Pacific Islanders and just 25 percent for whites.
"The atlas also highlights difference in geographical patterns between the five racial and ethnic groups," Casper said. For both blacks and whites, the geographical pattern was similar to that of the total population. Among Hispanics, however, the largest concentration of high-rate counties was observed in Texas and New Mexico. For American Indians, the highest mortality rates were further north, in Alaska, Oregon, Idaho and Montana. For Asians and Pacific Islanders, the highest rates turned up in California, Nevada, and the Pacific Northwest.
The atlas provides clues but not definitive answers as to why these disparities exist.
"It is important that the concentration of high-rate counties tends to be in areas of the country that have been chronically impoverished and underdeveloped," Casper said. "A persistent lack of social and economic resources makes it difficult for those communities to provide stroke-free living and working environments for their residents."
According to CDC officials, the maps included in the atlas will help pinpoint which communities and which ethnic groups need the most help when it comes to stroke prevention.
The components of an effective program? "Access to affordable quality health care; jobs with necessary health benefits; information about the signs and symptoms of a stroke; treatment and control of high blood pressure, which is the leading risk factor for stroke; universal 911 coverage with emergency medicine services, parks and recreational facilities, and sufficient leisure time to use them; foods high in fiber and low in fat, and smoking cessation programs," said Casper.