Excess Mortality in the United States, 2020-21: County-level Estimates for Population Groups and Associations with Social Vulnerability

To assess the excess mortality burden of Covid-19 in the United States, we estimated sex, age and race stratified all-cause excess deaths in each county of the US during 2020 and 2021. Using spatial Bayesian models trained on all recorded deaths between 2003-2019, we estimated 463,187 (95% uncertainty interval (UI): 426,139 - 497,526) excess deaths during 2020, and 544,105 (95% UI: 492,202 - 592,959) excess deaths during 2021 nationally, with considerable geographical heterogeneity. Excess mortality rate (EMR) nearly doubled for each 10-year increase in age and was consistently higher among men than women. EMR in the Black population was 1.5 times that of the White population nationally and as high as 3.8 times in some states. Among the 25-54 year population excess mortality was highest in the American Indian/Alaskan Native (AI/AN) population among the four racial groups studied, and in a few states was as high as 6 times that of the White population. Strong association of EMR with county-level social vulnerability was estimated, including positive associations with prevalence of disability (standardized effect: 40.6 excess deaths per 100,000), older population (37.6), poverty (23.6), and unemployment (18.5), whereas population density (-50), higher education (-38.6), and income (-35.4) were protective. Together, these estimates provide a more reliable and comprehensive understanding of the mortality burden of the pandemic in the US thus far. They suggest that Covid-19 amplified social and racial disparities. Short-term measures to protect more vulnerable groups in future Covid-19 waves and systemic corrective steps to address long-term societal inequities are necessary. Significance StatementAll-cause excess mortality estimates, the difference between observed all-cause deaths and deaths expected in the absence of a pandemic, can help more fully assess the pandemics burden than direct Covid-19 mortality. Our estimates, based on a 17-year record of all deaths in the US and a Bayesian spatial model, quantify the differences in excess mortality across counties and by population age, race and sex, as well as between the first and second years of the pandemic. Furthermore, our results indicate that population-level socioeconomic indicators such as poverty, unemployment and educational attainment had considerable effect on excess mortality during the pandemic. Sustained efforts to protect vulnerable populations during future waves of Covid-19 (and other public health emergencies) remain vital.