The actual number of global deaths from Covid-19 could be more than three times higher than official records suggest, a study has shown.
It is estimated that more than 18.2 million people may have died from coronavirus through the end of December last year.
This is despite the official Covid death toll indicating that 5.9 million people lost their lives between January 1 2020 and December 31, 2021.
Excess deaths — the difference between total deaths and the number expected based on past trends — are a key measure of the true death toll of the pandemic.
Although experts have made several attempts to estimate excess deaths from Covid, many have been limited by the availability of data.
The new study, published in The Lancet, provides the first peer-reviewed estimates of excess deaths — direct and indirect — due to the pandemic globally and for 191 countries and territories between January 2020 and December 2021.
Lead author Dr Haidong Wang, of the Institute for Health Metrics and Evaluation, said: “Understanding the true death toll from the pandemic is vital for effective public health decision-making.
“Studies from several countries, including Sweden and the Netherlands, suggest Covid-19 was the direct cause of most excess deaths, but we currently don’t have enough evidence for most locations.
“Further research will help to reveal how many deaths were caused directly by Covid-19 and how many occurred as an indirect result of the pandemic.”
Researchers collected weekly or monthly data on deaths from all causes in 2021, 2020 and up to 11 previous years for 74 countries and 266 states and provinces through searches of government websites, the World Mortality Database, the Human Mortality Database and the European Statistical Office.
The data were used in models to estimate excess deaths due to Covid-19, including in locations with no weekly or monthly reporting of death data.
The excess death rate is estimated to be 120 deaths per 100,000 people globally, but 21 countries were estimated to have rates of more than 300 excess deaths per 100,000.
The research shows rates of excess death are estimated to have varied significantly by country and region.
The highest estimated excess deaths were in Andean Latin America — 512 deaths per 100,000 people; Eastern Europe — 345 deaths per 100,000; Central Europe — 316 deaths per 100,000; Southern Sub-Saharan Africa — 309 deaths per 100,000; and Central Latin America — 274 deaths per 100,000.
Outside these regions, several locations are estimated to have had similarly high rates, including Lebanon, Armenia, Tunisia, Libya, several regions of Italy, and several states in the southern US.
However, in stark contrast, some countries were estimated to have had fewer deaths than expected based on trends in prior years.
These included Iceland, with 48 fewer deaths per 100,000; Australia, with 38 fewer deaths per 100,000; and Singapore, with 16 fewer deaths per 100,000.
South Asia had the highest number of estimated excess deaths from Covid, with 5.3 million excess deaths, followed by North Africa and the Middle East (1.7 million), and Eastern Europe (1.4 million).
At the country level, the highest number of estimated excess deaths occurred in India (4.1 million) and the US and Russia, both with 1.1 million.
Along with Mexico (798,000), Brazil (792,000), Indonesia (736,000) and Pakistan (664,000), these countries may have accounted for more than half of global excess deaths over the 24-month period studied, the research suggests.
Researchers say the large differences between excess deaths and official records may be because of under-diagnosis due to a lack of testing and issues with death data being reported.
They say it is crucial to distinguish between deaths caused directly by Covid and those that occurred as an indirect result of the pandemic.
Evidence from initial studies suggests a significant proportion of excess deaths were a direct result of coronavirus, however deaths may also have occurred indirectly from causes such as suicide or drug use due to behavioural changes or lack of access to health care and other essential services.
To date, only 36 countries have released cause of death data for 2020.
As data from more countries become available, scientists will have a better idea of how many deaths were caused directly by Covid and how many occurred as an indirect result.
The authors acknowledge a number of limitations to their study, including that a statistical model was used to predict excess deaths for countries that did not report weekly or monthly data.