Rates of stroke incidence, subsequent death decrease among black and white U.S. adults

The JAMA Network JournalsJul 16 2014

In a study that included a large sample of black and white U.S. adults from several communities, rates of stroke incidence and subsequent death decreased from 1987 to 2011, with decreases varying across age-groups, according to a study in the July 16 issue of JAMA.

Stroke ranks fourth among all causes of death in the U.S. and is recognized as a leading cause of serious physical and cognitive long-term disability in adults. Almost 800,000 Americans suffer a stroke each year, and over 600,000 of them are first-ever events. Stroke incidence varies by gender and ethnic group, according to background information in article.

Silvia Koton, Ph.D., of Johns Hopkins University School of Public Health, Baltimore, and colleagues examined trends in stroke incidence and subsequent death among black and white adults in the Atherosclerosis Risk in Communities (ARIC) cohort, a study of 15,792 residents in four communities in the U.S., ages 45 to 64 years at baseline (1987-1989). The communities were Minneapolis, Washington County, Md., Forsyth County, N.C., and Jackson, Mississippi. For this analysis, the researchers followed-up on 14,357 participants free of stroke at baseline for all stroke hospitalizations and deaths from 1987 to 2011.

During the study period, there were 1,051 (7 percent) participants with incident stroke. The researchers found a significant decrease in stroke incidence from 1987 to 2011 in both whites and blacks as well as men and women, but this decrease was seen only above age 65 years, with younger participants experiencing stable stroke incidence rates.

Of participants with incident stroke, 614 (58 percent) died through 2011, with analysis indicating a decrease in mortality during the last two decades, mostly due to a decrease among participants younger than 65 years. This decrease was generally similar in men and women and by race.

The authors speculate that "more successful control of risk-factors in the last decades, mainly hypertension control starting in the 1970s, and later, hypertension treatment combined with smoking cessation, control of diabetes and dyslipidemia, and treatment of atrial fibrillation may have resulted in lower stroke incidence and less severe strokes, which may account for the observed lower case-fatality rates."

"Whether the decline in stroke incidence and mortality will continue in older age groups is still speculative, and the absence of a decline in younger age groups could be an early warning sign," write Ralph L. Sacco, M.D., and Chuanhui Dong, M.D., Ph.D., of the University of Miami, in an accompanying editorial.

"Although there has been significant progress in reducing smoking and lowering blood pressure and cholesterol, formidable challenges to address stroke disparities and successfully control risk factors and lifestyle behaviors across race, ethnicity, and regions persist. Unless health disparities are addressed and innovative strategies to change behavior are developed and adopted, the cerebrovascular health of the population will be unlikely to improve. Greater improvements in brain health, especially with controllable risk factors such as diet, exercise, smoking, and obesity, among younger segments of the population are required to reduce the risk of stroke and enhance the chance of successful cognitive aging for all adults."