Stroke Prevalence Inches Upward in American Men

Stroke prevalence increased slightly in American men between 1999 and 2018 but remained stable in general among community-dwelling adults, national survey data showed.

From 1999 to 2018, the overall crude prevalence of self-reported stroke for both sexes was 2.84% (95% CI 2.67-3.02), with an age-standardized prevalence of 3.10% (95% CI 2.92-3.29), reported Wells Andres, MD, of the University of Pennsylvania in Philadelphia, during a session at the American Academy of Neurology annual meeting.

The findings were based on National Health and Nutrition Examination Survey (NHANES) data and were published simultaneously in a JAMA Neurology research letter.

"Overall, we found that the prevalence of stroke has remained stable over this time period -- an age-standardized prevalence of about 3%, which corresponds to between 7 and 8 million affected individuals," said co-author Andrea Schneider, MD, PhD, also of the University of Pennsylvania.

"The prevalence in men increased slightly over time -- in men, the age-standardized prevalence was 2.9% in 1999-2002 and 3.1% in 2015-2018 -- but was stable among other age, sex, race, and ethnic groups," Schneider told MedPage Today.

The study did not investigate reasons behind these trends, Schneider noted. "Important next steps for us are to investigate factors driving the overall stable prevalence over the past 20 years and the slightly increasing prevalence in men," she said.

The researchers used 1999-2018 NHANES data to estimate trends in the non-institutionalized civilian population of adults ages 20 and older. NHANES is a cross-sectional poll conducted annually by the CDC's National Center for Health Statistics. The analysis included 2,197 participants from the NHANES survey cycles who self-reported a history of stroke, which was ascertained with the question, "Has a doctor or other health professional ever told you that you had a stroke?"

Prevalence estimates were age-standardized into three categories: 20-39, 40-59, and 60 or older. Most people with stroke were 60 or older. "The age-standardized estimates take into account the changing age structure of the U.S. population over the time period, so trends reported represent true trends in stroke and not just a reflection of the population having more older individuals in it who are more likely to have a stroke," Schneider said.

Across 4-year epochs spanning from 1999 to 2018, crude estimates of the total number of people with self-reported stroke rose over time, but age-standardized estimates were stable. The age-standardized prevalence of stroke was higher among Black participants compared with other racial and ethnic groups and was similar by sex.

Except in men, prevalence was stable from 1999-2002 to 2015-2018 in each age and racial and ethnic group. In men, crude prevalence rose from 2.29% (95% CI 1.94-2.71) in 1999-2002 to 2.94% (95% CI 2.50-3.46) in 2015-2018, while age-standardized prevalence increased from 2.91% (95% CI 2.49-3.39) to 3.08% (95% CI 2.63-3.60, P for trend=0.04) in the same period.

"Prevalence data is important for public health because it gives an estimate about the burden of a disease in a population, which in turn guides decisions about resources for public health interventions," Schneider said. However, this study "underestimates the total burden of stroke in the U.S. as NHANES does not include individuals residing in rehabilitation, long-term care, or other institutional settings," she pointed out.

In addition, stroke was self-reported in NHANES, which has high negative predictive value but modest positive predictive value, the researchers noted.

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