Excess natural-cause mortality in US counties and its association with reported COVID-19 deaths

Abstract

In the United States, estimates of excess deaths attributable to the COVID-19 pandemic have consistently surpassed reported COVID-19 death counts. Excess deaths reported to non-COVID-19 natural causes may represent unrecognized COVID-19 deaths, deaths caused by pandemic health care interruptions, and/or deaths from the pandemic’s socioeconomic impacts. The geographic and temporal distribution of these deaths may help to evaluate which explanation is most plausible. We developed a Bayesian hierarchical model to produce monthly estimates of excess natural-cause mortality for US counties over the first 30 mo of the pandemic. From March 2020 through August 2022, 1,194,610 excess natural-cause deaths occurred nationally [90% PI (Posterior Interval): 1,046,000 to 1,340,204]. A total of 162,886 of these excess natural-cause deaths (90% PI: 14,276 to 308,480) were not reported to COVID-19. Overall, 15.8 excess deaths were reported to non-COVID-19 natural causes for every 100 reported COVID-19 deaths. This number was greater in nonmetropolitan counties (36.0 deaths), the West (Rocky Mountain states: 31.6 deaths; Pacific states: 25.5 deaths), and the South (East South Central states: 26.0 deaths; South Atlantic states: 25.0 deaths; West South Central states: 24.2 deaths). In contrast, reported COVID-19 death counts surpassed estimates of excess natural-cause deaths in metropolitan counties in the New England and Middle Atlantic states. Increases in reported COVID-19 deaths correlated temporally with increases in excess deaths reported to non-COVID-19 natural causes in the same and/or prior month. This suggests that many excess deaths reported to non-COVID-19 natural causes during the first 30 mo of the pandemic in the United States were unrecognized COVID-19 deaths.

Cause-Specific Excess Mortality in the US During the COVID-19 Pandemic

“…The proportion of deaths at home also increased during the pandemic 35 , reducing the opportunity for a COVID-19 diagnosis. The political polarization of COVID-19 in the US may have contributed to underreporting that varied by geography 36 . In addition to misattributed COVID-19 mortality, increases in CVD mortality may have occurred due to disruptions in routine or emergency health services during COVID-19 peaks 37 or healthcare avoidance due to fear of infection.…”

Unrecognised COVID-19 deaths in central Europe: The importance of cause-of-death certification for the COVID-19 burden assessment

“…Most recent studies aim to assess the number of unrecognised COVID-19 deaths [ 23 ], but the COVID-19 mentions reported as a comorbidity have never been examined for this purpose. Our study found that 8% of death certificates citing COVID-19 reported it only as a comorbidity, more frequently in Austria, Bavaria, Czechia and Lithuania than in Poland.…”

“…While the importance of these factors can be approximated by studying mortality from causes other than COVID-19, the scale of unrecognised coronavirus cases has rarely been explored due to lack of data and methods. The most recent study [ 23 ] showing that peaks in COVID-19 deaths were preceded at short time intervals by peaks of all-cause mortality in some regions of the United States is a novelty in this respect. This study shows that despite the complexity of the pathophysiological process leading to death in the presence of SARS-CoV-2, the use of MCoD data and metrics allows us to overcome some of the ambiguity of certification practices and to assess the overall burden of COVID-19.…”

“…Studies that estimate the excess mortality during the pandemics beyond registered COVID-19 deaths do not distinguish between different factors underlying excess mortality during the pandemic [ 3 ] and do not consider the unrecognised coronavirus deaths separately from other deaths. In countries where detailed information on the time of death is available, unrecognised coronavirus deaths can be estimated based on statistical correlations between time series of deaths due to COVID-19 and other natural causes [ 23 ]. In countries where no such information is available, the multiple cause-of-death (MCoD) approach is useful.…”