Conflicting COVID-19 excess mortality estimates

Excess mortality is an important metric summarising COVID-19 disease burden, informing public health policy and future preparedness needs.1Vestergaard LS Mølbak K Timely monitoring of total mortality associated with COVID-19: informing public health and the public.Euro Surveill. 2020; 25: 2001591Crossref Google Scholar However, separating the deaths that occurred from COVID-19 versus those from all other causes is challenging. Essentially, the unknowns are the counterfactual, should an infection wave not have happened. A solution to this challenge is to estimate expected number of individuals who would have died and compare this with the observed number of deaths. The estimation of expected number of deaths must consider changes in population and seasonal dynamics and be based on an appropriate reference period. The COVID-19 Excess Mortality Collaborators2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar present an important study that estimates 18·2 million excess deaths spread across 191 countries and territories in the first 2 years of the COVID-19 pandemic, 2020 and 2021. The authors use an ensemble-based approach to estimate global excess mortality due to data paucity in many countries. Although this global estimate might be broadly correct and serves as an important reminder of the effect of COVID-19, we strongly caution against the over-interpretation of the constituent country estimates. For European countries, we instead recommend the use of EuroMOMO—a standard and coordinated approach for mortality monitoring in Europe. EuroMOMO estimates expected excess mortality, correcting for delay in registration and changes in population and seasonality during a 5-year reference period.3Nielsen J Mazick A Andrews N et al.Pooling European all-cause mortality: methodology and findings for the seasons 2008/2009 to 2010/2011.Epidemiol Infect. 2013; 141: 1996-2010Crossref PubMed Scopus (0) Google Scholar EuroMOMO excess mortality estimates include both surplus and deficit mortality, with deficit mortality expected under stringent control restrictions. Whether the COVID-19 Excess Mortality Collaborators2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar consider both surplus and deficit mortality is unclear. We find conflicting estimates of excess mortality for several countries with reliable and near complete mortality reporting. For example, for Denmark, the authors2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar predicted an excess mortality of 203% higher than the estimate from EuroMOMO. The trend in increasing excess mortality in the later part of 2021 estimated by the study2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar is inconsistent with trends reported from the Danish health authorities, the total mortality, and the EuroMOMO excess mortality. The COVID-19 Excess Mortality Collaborators2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar do not provide details on these discrepancies and do not provide their weights and background estimates for all countries. Because of the inconsistencies shown in our table (appendix p 1), we caution both the use and over-interpretation of individual country estimates from the study.2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar Although the estimates from this study2COVID-19 Excess Mortality CollaboratorsEstimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21.Lancet. 2022; 399: 1513-1536Summary Full Text Full Text PDF PubMed Scopus (222) Google Scholar are important in a global perspective, for individual countries with good health-care reporting, nationally reported estimates (eg, from EuroMOMO) are probably more reliable. For more on EuroMOMO see: https://www.euromomo.eu/] For more on EuroMOMO see: https://www.euromomo.eu/] We declare no competing interests. Download .pdf (.75 MB) Help with pdf files Supplementary appendix Conflicting COVID-19 excess mortality estimates – Authors' replyThe COVID-19 pandemic has caused almost 8 million reported deaths worldwide since late 2019.1 Although this is a staggering loss of human lives, 8 million is a vast under-estimation of the true toll of the pandemic. In addition to under-reporting and misclassification of COVID-19 deaths, the pandemic has also resulted in loss of lives due to stressed health-care systems. Excess mortality due to the COVID-19 pandemic, a measurement of net changes in all-cause mortality during the pandemic compared with levels before the pandemic, is widely considered the best measurement of the overall effect of the pandemic and is increasingly a metric used to compare country performance with expectations. Full-Text PDF Conflicting COVID-19 excess mortality estimatesA study1 by the COVID-19 Excess Mortality Collaborators estimates more than 18 million COVID-19 deaths globally by the end of 2021—three times those reported. The COVID-19 Excess Mortality Collaborators claim that under-ascertainment is especially severe in sub-Saharan Africa, with actual deaths 14 times higher than the 150 000 reported—more than 2 million excess deaths across the region in 2020–21. Full-Text PDF Conflicting COVID-19 excess mortality estimatesAlthough the global review of excess deaths from the COVID-19 pandemic might seem to give authorities in some countries encouragement for their policies,1 it seems unfortunate that a key vulnerable group was missing from discussion in the paper. Full-Text PDF Conflicting COVID-19 excess mortality estimatesTo estimate the COVID-19 death toll, the COVID-19 Excess Mortality Collaborators1 have presented excess mortality estimates for 2020–21 for all countries in the world. We argue that for many countries, these estimates are implausible because they imply an unrealistic number of expected deaths, inconsistent with trends before the pandemic. A case in point is Japan, where the authors estimated 111 000 (95% CI 103 000–116 000) excess deaths from Jan 1, 2020, to Dec 31, 2021—an order of magnitude higher than the estimate by The Economist2 (12 000) and qualitatively different from the World Mortality Dataset's3 negative estimate (–13 100). Full-Text PDF Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020–21The full impact of the pandemic has been much greater than what is indicated by reported deaths due to COVID-19 alone. Strengthening death registration systems around the world, long understood to be crucial to global public health strategy, is necessary for improved monitoring of this pandemic and future pandemics. In addition, further research is warranted to help distinguish the proportion of excess mortality that was directly caused by SARS-CoV-2 infection and the changes in causes of death as an indirect consequence of the pandemic. Full-Text PDF Open AccessConflicting COVID-19 excess mortality estimatesThe COVID-19 Excess Mortality Collaborators concluded that “The full impact of the pandemic has been much greater than what is indicated by reported deaths due to COVID-19 alone”. They estimate that 18·2 million (95% CI 17·1–19·6) people died worldwide because of the pandemic (as measured by excess mortality) in 2020–21, instead of the reported COVID-19 deaths of 5·94 million worldwide during that period, as WHO claims. Full-Text PDF