The incidence and mortality rates of first-time strokes were shown to decline over the last 20 years in the U.S. The results from the analysis were striking in that the overall decline was shown to be at a level of 24 percent and there was a 20 percent reduction in death after a stroke.
The study was conducted by researchers at the Johns Hopkins Bloomberg School of Public Health and the results from the study were reported in the journal JAMA. Data from the Atherosclerosis Risk in Communities Study from 1987 to 2011 were considered in the analysis to determine the trends regarding strokes and to assess potential differences in race regarding strokes. Data from a total of 14,357 people were included in the study.
The Atherosclerosis Risk in Communities Study is a very large ongoing study sponsored by the National Heart, Lung, and Blood Institute. Its purpose is to determine the epidemiology of atherosclerosis, strokes and risk factors. Variations in medical care, race, and gender are also considered. Four communities were chosen for the study and a cohort of about 4,000 people who were 45-64 years old from each community were enrolled in the study between 1987 and 1989. The four communities are Washington County, MD, Forsyth County, NC, Jackson, MS and Minneapolis, MN. Participants in the study have been followed up periodically since the beginning of the study. Currently, data gathered up to 2011 is available for researchers to analyze.
There were differences in how much the incidence decreased for different age groups but there were no differences in decreases for sex and race. In this study, the analysis regarding race was limited to two categories; that is, black and white. Age was divided into two groups; that is, less than 65 years old and greater than 65 years old. The decline in the incidence rate of strokes was seen in people over the age of 65 years old but not for younger people. However, the rate of mortality remained the same in the older age group while the drop in the mortality rate due to stroke was noted in the younger age group.
The researchers offered some suggestions about factors that may have played a role in the decline in the incidence of stroke. These factors included better control of cholesterol and blood pressure, improvements in medical care following a stroke and the reduction of smoking in the population over the last 20 years. Smoking has been shown to be a major factor in risk for stroke. It has been reported that the risk of stroke is twice as likely in someone who smokes compared to someone who does not smoke.
Even though the study results are considered to be good news, stroke is still a major cause of disability and death in the U.S. Strokes are estimated to be the fourth leading cause of death in the U.S. It has been reported that strokes affect 795,000 people in the U.S. per year. Stroke risk remains a major medical concern, however, observing a decline in the incidence of stroke over the last 20 years is an indication that positive progress is being made.
By Margaret Lutze