The impact of the pandemic on non-COVID-19 causes of death in the United States: a multiple cause of death analysis

Multiple cause of death data allow for a more granular analysis of the pandemic's impact on mortality from non-COVID-19 causes of death compared with analysis of a single underlying cause of each death because they are often a co-morbidity of COVID-19. This study estimates excess mortality in the US of non-COVID-19 causes measured as a multiple cause (reported anywhere on the death certificate). Death registration data were used to conduct Poisson regressions of 24 non-COVID-19 causes to estimate expected age-standardized death rates and excess mortality in 2020-21, including by place of death. The ratio of COVID-19 mortality (as underlying or contributing cause) to excess mortality of each non-COVID-19 cause was calculated. During 2020-21, 21 of 24 non-COVID-19 causes exhibited excess mortality, highest for pneumonia (males 126.5%; 95% confidence interval 116.6-136.9%), other respiratory diseases (males 45.2%; 42.2-48.2%), other kidney diseases (males 45.0%, 37.8-52.0%), diabetes (females 38.3%, 32.8-43.4%) and hypertensive heart disease (females 28.9%, 22.8-33.9%). Suicide and influenza mortality was lower than expected. The ratio of COVID-19 (underlying cause) to excess mortality was 74.2% (69.2-79.7%) for men and 68.7% (63.5-75.0%) for women, was significantly higher for hospital (over 90%) than home (less than 16%) deaths and varied greatly between causes. The pandemic led to excess mortality for almost all non-COVID-19 causes in the US when measured as a multiple cause, being particularly high in several non-communicable diseases that increase the risk of dying from COVID-19. COVID-19 appears underreported for home deaths due to its low ratio to excess mortality in this setting.