State-Level Excess Mortality in US Adults During the Delta and Omicron Waves of COVID-19 (preprint)

ABSTRACT

Introduction The US has continued to see excess mortality through the Delta and Omicron periods. We sought to quantify excess mortality on a state level and calculate potential deaths averted if all states matched the excess mortality rates of those with the 10 lowest excess mortality rates. Methods Observational cohort, US and state-level data. Expected monthly deaths were modeled using pre-pandemic US and state-level data (2015-2020). Mortality data was accessed from CDC public reporting. Results We find that during the Delta and Omicron waves, the US recorded over 596,000 excess deaths. 60% of the nation's total excess mortality during these periods could have been averted if all states had excess mortality rates equal to those with the 10 lowest excess mortality rates. Conclusion With large differences in excess mortality across US states in our 15-month study period, we note that a significant portion of deaths could have been averted with higher vaccination rates, policies and other behaviors.