@article {Kung00766-2020, author = {Stacey Kung and Marjan Doppen and Melissa Black and Irene Braithwaite and Cil{\'e}in Kearns and Mark Weatherall and Richard Beasley and Nethmi Kearns}, title = {Underestimation of COVID-19 mortality during the pandemic}, volume = {7}, number = {1}, elocation-id = {00766-2020}, year = {2021}, doi = {10.1183/23120541.00766-2020}, publisher = {European Respiratory Society}, abstract = {Background There has been considerable international variation in mortality during the COVID-19 pandemic. The objective of this study was to investigate the differences between mortality registered as due to COVID-19 and the excess all-cause mortality reported in countries worldwide during the COVID-19 pandemic.Methods Ecological analysis of 22 countries compared 5-year historical all-cause mortality, reported all-cause mortality and expected all-cause mortality (calculated as historical mortality plus the reported deaths attributed to COVID-19). Data available from the first week of January 2020 to that most recently available were analysed.Results Compared to the preceding 5 years, there was an excess of 716 616 deaths, of which 64.3\% were attributed to COVID-19. The proportion of deaths registered as COVID-19-related/excess deaths varied markedly between countries, ranging between 30\% and 197\% in those countries that had an excess of deaths during the period of observation. In most countries where a definite peak in COVID-19-related deaths occurred, the increase in reported all-cause mortality preceded the increase in COVID-19 reported mortality. During the latter period of observation, a few countries reported fewer all-cause deaths than the historical figures.Conclusion The increases in all-cause mortality preceded the increase in COVID-19 mortality in most countries that had definite spikes in COVID-19 mortality. The number of deaths attributed to COVID-19 was underestimated by at least 35\%. Together these findings suggest that calculation of excess all-cause mortality is a better predictor of COVID-19 mortality than the reported rates, in those countries experiencing definite increases in mortality.In countries experiencing marked increases in all-cause mortality during the global pandemic, all-cause mortality more accurately estimates $\#$COVID19 mortality and the onset of the pandemic than the reported COVID-19 mortality rates https://bit.ly/3fOtBJg}, URL = {https://openres.ersjournals.com/content/7/1/00766-2020}, eprint = {https://openres.ersjournals.com/content/7/1/00766-2020.full.pdf}, journal = {ERJ Open Research} }