The COVID Excess Mortality Percentage and Racial/Ethnic Disparities in COVID Mortality: Evidence from Indiana and Wisconsin
28 Pages Posted: 2 Nov 2022
Date Written: October 10, 2022
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. We 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: We 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: We 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: We 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.
The Online Appendix is available at: http://ssrn.com/abstract=4244054
Funding Information: Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR001436. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
Conflict of Interests: The authors have no competing interests
Ethical Approval: The project was approved by the Medical College of Wisconsin Human Research Review Board.
Keywords: COVID-19; COVID-19 Mortality rate; Racial / Ethnic Disparities; COVID Excess Mortality Percentage
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