The COVID Excess Mortality Percentage and Racial-Ethnic Disparities in COVID Mortality: Evidence from Indiana and Wisconsin (WP-22-45)
Vladimir Atanasov, Paula Natalia Barreto Parra, Lorenzo Franchi, Jeffrey Whittle, John Meurer, Qian (Eric) Luo, Andy Yuan, Ruohao Zhang, and Bernard Black
Importance: COVID-19 mortality rates increase with age, are higher among men than women, and vary across racial/ethnic groups, but this is also true for other natural causes of death. The authors develop a new measure of COVID-19 mortality burden, the COVID Excess Mortality Percentage (CEMP), defined as COVID-19 deaths as a fraction of all deaths from natural causes other than COVID-19. This measure can control for the effects of underlying population characteristics, including general population health, age, gender, race/ethnicity, and zip-code-level socioeconomic status (zip-SES) in predicting the COVID-19 mortality burden. Objective: They use CEMP to study how COVID-19 mortality varies by age, gender, race/ethnicity, and zip-SES and between the pre-vaccine and vaccine-available periods. Design: Retrospective analysis of all deaths from natural causes. Setting: Indiana and Wisconsin. Participants: All adult decedents from natural causes over the pandemic period from April 2020-March 2022. Exposure: Demographic factors and vaccine availability. Main Outcome and Measures: They report CEMP within sub-populations defined by age, gender, and race/ethnicity during the pre-vaccine (April 2020-March 2021) and vaccine-available (April 2021-March 2022) periods, and odds ratios from multivariable logistic regression.
Results: CEMP is broadly similar for men and women and rises gradually with age during the pre-vaccine period, but peaks at age 40-49 during the vaccine-available period. Racial/ethnic disparities can be very high, especially for Hispanics in the pre-vaccine period, with CEMP ratios for Hispanics to non-Hispanic Whites as high as 9:1 for men aged 50-59, and higher for men than for women. CEMP disparities were smaller but substantial for other minorities and declined with age after 60+. Differences in zip-SES and education explain only a small part of these disparities. National results for 2020 are consistent with our Indiana-Wisconsin findings.
Conclusions and Relevance: The authors studied COVID-19 mortality using a new measure that controls for non- COVID natural mortality rates. This approach is important in understanding racial/ethnic disparities in COVID-19 mortality. Disparities have been observed before, but not the very high Hispanic/White ratios we find for younger and middle-aged persons, especially men. Explanations for these disparities must account for age, gender, and time variation.
Key Points: Question. By how much did COVID-19 increase mortality rates; how did this vary with age, gender, and race/ethnicity; and with whether vaccines were available? Findings. The COVID Excess Mortality Percentage (CEMP) rose with age during the pre- vaccine period, but peaked at ages 40-49 in the vaccine-available period. Pre-vaccine CEMP rates were dramatically higher for Hispanics than non-Hispanic Whites; especially non-elderly men, and were also elevated for non-elderly Blacks and “other” race persons. Disparities shrank in the vaccine-available period. Meaning. The large racial/ethnic disparities in non-elderly CEMP rates, are not explained by underlying health status and call for detailed investigation.