Stroke Mortality Among Black and White Adults Aged ≥35 Years Before and During the COVID-19 Pandemic — United States, 2015–2021

Stroke is the fifth leading cause of death and a leading cause of long-term disability in the United States (1). Although stroke death rates have declined since the 1950s, age-adjusted rates remained higher among non-Hispanic Black or African American (Black) adults than among non-Hispanic White (White) adults (1,2). Despite intervention efforts to reduce racial disparities in stroke prevention and treatment through reducing stroke risk factors, increasing awareness of stroke symptoms, and improving access to treatment and care for stroke (1,3), Black adults were 45% more likely than were White adults to die from stroke in 2018.* In 2019, age-adjusted stroke death rates (AASDRs) (stroke deaths per 100,000 population) were 101.6 among Black adults and 69.1 among White adults aged ≥35 years. Stroke deaths increased during the early phase of the COVID-19 pandemic (March–August 2020), and minority populations experienced a disproportionate increase (4). The current study examined disparities in stroke mortality between Black and White adults before and during the COVID-19 pandemic. Analysts used National Vital Statistics System (NVSS) mortality data accessed via CDC WONDER^† to calculate AASDRs among Black and White adults aged ≥35 years prepandemic (2015–2019) and during the pandemic (2020–2021). Compared with that during the prepandemic period, the absolute difference in AASDR between Black and White adults during the pandemic was 21.7% higher (31.3 per 100,000 versus 38.0). During the pandemic period, an estimated 3,835 excess stroke deaths occurred among Black adults (9.4% more than expected) and 15,125 among White adults (6.9% more than expected). These findings underscore the importance of identifying the major factors contributing to the widened disparities; implementing prevention efforts, including the management and control of hypertension, high blood cholesterol, and diabetes; and developing tailored interventions to reduce disparities and advance health equity in stroke mortality between Black and White adults. Stroke is a serious medical condition that requires emergency care. Warning signs of a stroke include sudden face drooping, arm weakness, and speech difficulty. Immediate notification of Emergency Medical Services by calling 9-1-1 is critical upon recognition of stroke signs and symptoms.

Annual AASDRs (calculated using 2000 U.S. Census Bureau standard population) and 95% CIs for Black and White adults aged ≥35 years were calculated for 2015–2020 (using final underlying cause of death data stratified by bridged-race categories) and 2021 (using underlying cause of death data stratified by single-race categories as of March 20, 2023) using CDC WONDER mortality data based on place of residence data from death certificates filed in the 50 U.S. states and the District of Columbia. AASDRs and 95% CIs were then calculated for the prepandemic and pandemic periods. International Classification of Diseases, Tenth Revision cause of death codes I60–I69 (cerebrovascular disease) were used to classify stroke as the underlying cause of death. This study included persons listed as having one race (Black or White) and non-Hispanic or Latino ethnicity.^§ Disparities between Black and White adults were measured using absolute and relative differences. The absolute difference in AASDR among adults aged ≥35 years (rate among Black adults minus rate among White adults) was calculated for the prepandemic and pandemic periods and compared. The relative difference was measured by rate ratios calculated as AASDR among Black adults divided by AASDR among White adults. The 95% CIs for the absolute and relative differences were estimated. Nonoverlapping 95% CIs for rates, absolute differences, or relative differences between two periods or two groups (e.g., women versus men) were considered statistically significant. Analyses were stratified by sex and age group (35–64, 65–84, and ≥85 years).

Excess stroke deaths for Black and White adults during the pandemic were estimated as follows: 1) annual percent changes (APC) in the sex-, age-, and race and ethnicity–specific stroke death rates during 2015–2019 were estimated; 2) expected rates for 2020 and 2021 were calculated, assuming the APC during 2015–2019 would continue during 2020–2021; 3) the expected number of stroke deaths was obtained by multiplying the sex-, age-, and race and ethnicity–specific population by the expected stroke death rates; and 4) excess stroke deaths were calculated as the number of stroke deaths observed minus the number expected^¶ (5). Analyses were conducted using SAS software (version 9.4; SAS Institute) and Joinpoint (version 4.8.1.0; National Cancer Institute). This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.**

During 2015–2019, AASDR remained consistent for both Black (range = 100.5–102.0 [with a slight trend of increased rates]) and White adults (range = 69.1–70.6 [with a slight trend of decreased rates]); the average absolute difference was 31.3 per 100,000, and the average relative difference was 1.4. The relative differences in stroke mortality between Black and White adults were higher among men than women, and decreased with increasing age (Table 1) (Figure). During the COVID-19 pandemic, AASDR increased among both populations, but the increase was larger among Black adults; the average AASDR among Black adults increased 11.2% (from 101.3 to 112.6), compared with 6.6% (from 70.0 to 74.6) among White adults. The absolute difference in AASDR between Black and White adults increased 21.7% (from 31.3 to 38.0), and the average relative difference increased to 1.5. The patterns of increased disparities in stroke mortality, as measured by percent change in absolute differences, during the pandemic were similar among men and women and increased with increasing age. The absolute difference in AASDR between Black and White adults increased 10.9% (from 16.6 to 18.4) among persons aged 35–64 years and 19.4% (from 89.8 to 107.2) among persons aged 65–84 years. During the prepandemic period, annual stroke mortality rates among persons aged ≥85 years were lower among Black than among White adults (2). The absolute difference in this age group changed from −23.7 during 2015–2019 to 30.3 per 100,000 during 2020–2021 (Table 1). During 2020–2021, an estimated 3,835 excess stroke deaths occurred among Black adults (9.4% more than expected), and 15,125 excess stroke deaths occurred among White adults (6.9% more than expected). The estimated percentage of excess stroke deaths among both Black and White adults was higher among women and decreased with increasing age (Table 2).

¹Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, CDC.

References

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Abbreviations: AASDR = age-adjusted stroke death rate; BNH = Black or African American, non-Hispanic; WNH = White, non-Hispanic.
* Persons listed as BNH or WNH (not including those with race listed as “more than one race” or Hispanic ethnicity listed as “not stated”) were included in this study.
^† Per 100,000 persons, standardized to the 2000 U.S. Census Bureau population by age group (35–54, 55–64, 65–74, 75–84, and ≥85 years).
^§ For AASDRs, 95% CIs are calculated using Anderson-Rosenberg methods with the normal approximations of the 95% CIs (https://www.cdc.gov/nchs/data/nvsr/nvsr47/nvs47_03.pdf). For absolute and relative differences in rates, and percent change of absolute difference in rates between BNH and WNH adults (2020–2021 versus 2015–2019), 95% CIs are estimated by the Monte Carlo simulation–based approach by sampling 5,000 normal distributions based on the AASDRs and SEs and defining the CIs as the 2.5 and 97.5 percentiles of the simulation results using @Risk software (version 8.3.2; Palisade). https://help.palisade.com/v8/en/Guides/@RISK-Getting-Started-Guide.pdf
^¶ Percent change of absolute difference in rates in 2015–2019 versus 2020–2021 between BNH and WNH adults is calculated by 1) calculating the difference of the average absolute difference in rates between BNH and WNH adults in 2020–2021 and the average absolute difference in rates between BNH and WNH adults in 2015–2019, and 2) dividing the above difference by the average absolute difference in rates between BNH and WNH adults in 2015–2019 and multiplying by 100.
** Relative difference in rates are AASDRs among BNH divided by AASDRs among WNH adults. The percent change in absolute differences between BNH and WNH adults in 2015–2019 compared with 2020–2021 might be different based on the results presented in the table because of rounding the results to one-decimal point.

FIGURE. Age-adjusted stroke death rates* per 100,000 Black and White adults^† aged ≥35 years, before and during^§ the COVID-19 pandemic — United States, 2015–2021

* Per 100,000 persons, standardized to the 2000 U.S. Census Bureau population by age group (35–54, 55–64, 65–74, 75–84, and ≥85 years).

^† Persons listed as Black or African American or White (not including those listed as “more than one race”) and listed as non-Hispanic or Latino (not including those with Hispanic ethnicity listed as “not stated”) were included in this study.

^§ The period before the pandemic was defined as 2015–2019 and the period during the pandemic as 2020–2021.

Abbreviation: AASDR = age-adjusted stroke death rate.
* Persons listed as Black or African American or White (not including those listed as “more than one race”) and non-Hispanic or Latino (not including those with Hispanic ethnicity listed as “not stated”) were included in this study.
^† The expected number of stroke deaths were obtained by 1) assuming that the sex-, age-, and race and ethnicity–specific stroke death rates would continue through 2021 at the annual rate of 2015–2019 as identified by joinpoint analysis and 2) multiplying the sex-, age-, and race and ethnicity–specific population with the expected sex-, age-, and race and ethnicity–specific stroke death rates for 2020 and 2021. The expected number of stroke deaths by sex and age group might not sum to the total number of expected stroke deaths because of rounding.
^§ Excess stroke deaths were calculated based on the difference between the observed versus expected stroke deaths by sex, age, and race and ethnicity during 2020–2021. The percentages of excess stroke deaths were calculated by number of excess stroke deaths divided by number of expected stroke deaths multiplied by 100. The estimated excess number of stroke deaths by sex and age group might not sum to the total number of estimated excess stroke deaths because of rounding. The percentages of estimated excess stroke deaths among non-Hispanic Black or African American persons (9.4%) were lower than the changes in AASDR from prepandemic to during the pandemic periods (11.2%) because of the slight trend of increased AASDR during 2015–2019. The percentages of estimated excess stroke deaths among non-Hispanic White persons (6.9%) were slightly higher than the changes in AASDR from prepandemic to during the pandemic periods (6.6%) because of the slight trend of decreased AASDR during 2015–2019.