Decreased racial and ethnic disparities in COVID-19 mortalities between the first and Omicron waves of the pandemic could be explained by increased deaths in non-Hispanic White adults and changes in the geographic spread of the pandemic.
There has been extensive research into racial and ethnic disparities in COVID-19 mortalities in the US.
In 2020, Hispanic and non-Hispanic Black Americans experienced COVID-19 mortalities that were disproportionately higher than those of non-Hispanic White Americans. However, these disparities lessened in 2021.
A new original investigation, published today in JAMA Network Open, sought to determine why racial and ethnic disparities in COVID-19 mortality rates decreased during the Omicron wave of the pandemic, in comparison to the initial outbreak of COVID-19.
The study authors wanted to assess whether national decreases in racial and ethnic COVID-19 mortality disparities between the original pandemic wave and the Omicron wave actually reflect mortality decreases, or if the lowered disparity was due to other factors.
The cross-sectional study utilized data from the US Centers for Disease Control and Prevention (CDC) on COVID-19 deaths from March 1, 2020-February 28, 2022. Included mortalities occurred in adults 25 years and older who resided in the US.
The investigators compared the COVID-19 deaths by race and ethnicity across metropolitan and nonmetropolitan areas. They analyzed the decrease in racial and ethnic COVID-19 mortality disparities between the initial and Omicron waves. The primary study outcome was age-standardized death rates.
During the March 1, 2020-February 28, 2022 study period, there were 977018 death certificates for US adults that mentioned COVID-19. The mortalities averaged 73.6 years of age, 44.6% female, 16.1% Hispanic, 14.4% non-Hispanic Black, and 64.4% non-Hispanic White. In the initial wave of the COVID-19 pandemic, the proportion of COVID-19 deaths in adults living in nonmetropolitan areas rose from 5944 of 110526 deaths (5.4%) to a peak of 40360 of 172515 deaths (23.4%) during the Delta wave. During the Omicron wave, this proportion was 45183 of 210554 deaths (21.5%).
The US disparity in age-standardized COVID-19 deaths for non-Hispanic Black adults, compared to non-Hispanic White adults, decreased from 339 to 45 deaths per 100000 person-years from the pandemic outbreak to the Omicron wave.
These results initially suggested that racial and ethnic disparities in COVID-19 mortality decreased nationally for some groups in the first 2 years of the COVID-19 pandemic. However, this decrease could be attributed to increased mortalities in non-Hispanic White adults and changes in pandemic geography.
After standardizing the results for age, racial, and ethnic differences by metropolitan versus nonmetropolitan residence, increased mortality rates in non-Hispanic White adults accounted for 120 deaths per 100000 person-years of the decrease (40.7%). Shifts in mortality to nonmetropolitan areas accounted for 58 deaths per 100000 person-years, for a 19.6% decrease. This can be explained by a disproportionately high number of non-Hispanic White Americans living in nonmetropolitan areas.
The remaining 116 deaths per 100000 person-years in the 39.6% decrease were explained by decreased death rates in non-Hispanic Black adults.
The investigators concluded that most of the decrease in racial and ethnic disparities in COVID-19 mortalities between the first and Omicron waves of the pandemic could be explained by increased deaths in non-Hispanic White adults and changes in the geographic spread of the pandemic. “These findings suggest that despite media reports of a decline in disparities, there is a continued need to prioritize racial health equity in the pandemic response,” the study authors wrote.