A new paper in the Lancet has attracted some interest, both because it claims to find that the pandemic death toll is over three times higher than official Covid death figures suggest and because it seems to confirm that restrictions made no difference to outcomes. The authors say that while “reported COVID-19 deaths between January 1st 2020 and December 31st 2021 totalled 5·94 million worldwide”, they estimate that “18·2 million people died worldwide because of the COVID-19 pandemic (as measured by excess mortality) over that period”.
However, the paper is heavily dependent on modelling, so despite the welcome implication for the ineffectiveness of lockdowns, caution is needed.
The paper aims to “estimate excess mortality from the COVID-19 pandemic in 191 countries and territories, and 252 subnational units for selected countries, from January 1st 2020 to December 31st 2021”.
The relevant data were not always available, however, so the authors “built a statistical model that predicted the excess mortality rate for locations and periods where all-cause mortality data were not available”.
Not all excess deaths are Covid deaths, of course. The authors say that although they “suspect most of the excess mortality during the pandemic is from COVID-19”, excess deaths also include deaths from lockdown, including “deaths from chronic and acute conditions affected by deferred care-seeking”. However, there are currently insufficient data to distinguish Covid deaths from other excess deaths, they say, and while audits in Belgium and Sweden have suggested that excess deaths and Covid deaths are of a similar magnitude, audits in Russia and Mexico have suggested otherwise, as a “substantial proportion of excess deaths could not be attributed to SARS-CoV-2 infection in these locations”.
The authors used an ensemble of six models to estimate expected and thus excess deaths: “Excess mortality over time was calculated as observed mortality, after excluding data from periods affected by late registration and anomalies such as heat waves, minus expected mortality. Six models were used to estimate expected mortality; final estimates of expected mortality were based on an ensemble of these models.”