More than 20.5 million years of life have been lost around the world since the Covid-19 outbreak began, a study has shown. The report, based on data from 81 countries, lays bare the devastating loss caused by the pandemic and estimated that an average of 16 years of life have been lost from each death from Covid-19. While highlighting the scale of the pandemic, the study may underestimate years of life lost (YLL) – calculated by comparing a person's age at death with their expected lifespan – because it uses figures from early January and excludes dozens of nations. Published in the journal <em>Scientific Reports</em>, the research looked at life expectancy information and country-by-country projections of total Covid-19 fatalities when considering 1,279,866 deaths. An estimated 20,507,518 years of life were lost in the 81 countries by early January, according to the research, which was led by the Centre for Research in Health and Economics in Barcelona. The researchers calculated that in the worst-hit nations the pandemic caused the loss of between two and nine times as many years of life as seasonal influenza. While older people are more likely to die from Covid-19, the study indicates that younger patients have been heavily affected in actual years of life lost, because each death of a younger person exacts a greater toll in YLL. As a result, almost one third of YLL lost – 30.2 per cent – are in people aged less than 55, while 44.9 per cent are those between 55 and 75 and 25 per cent are in over-75s. "Most deaths at younger ages are occurring in less developed countries, due to the fact that there is a higher prevalence of comorbidities at younger ages," said the study's lead author, Dr Hector Arolas. “The overall result (one third of YLL have been in under-55s) is in fact the combination of less developed countries, with a high proportion of YLL attributed to younger ages, and developed countries, for which most YLL are concentrated in the oldest age group (75+).” Men have been more heavily affected, with a 44 per cent higher number of years of life lost than women, the researchers found. The amount of years of life lost because of the pandemic is estimated to be between one quarter and half that caused by heart conditions, the world's biggest killer. Prof John Oxford, an infectious diseases expert from the University of London not connected to the study, said he thought the effect of the pandemic could have been lessened if some countries acted more quickly to control the spread of infection. “Countries that reacted fast have had fewer deaths overall,” he said. “There’s a lot to be gone over when this outbreak begins to die down and we look at what happened in an objective way. “We’re going to find some countries need a good, hard kick and others less so. We can all probably learn from each other.” While Covid-19 has caused significant loss of life, Prof Oxford said its effect in years of life lost has been much smaller than the Spanish flu pandemic between 1918 and 1920, which killed an estimated 50 million people. “It doesn’t even approach the Spanish flu, because most people who died were young. If you’re a young person, you’re going to lose 60 years of life,” he said. In recent times, HIV/Aids – officially classified as a global epidemic – has killed more than 30 million people over several decades, according to UN estimates. The Covid-19 study is based on data up to January 6, by which time World Health Organisation figures indicated that more than 1.8 million people had lost their lives from the disease, almost 50 per cent more than the total included in the study. Since then, the pandemic has been blamed for more than half a million more deaths, bringing the global death toll to more than 2.4 million, according to WHO data. The effect of the pandemic has varied widely between continents. The Americas have recorded in excess of 1.1 million deaths, Europe more than 823,000 and South-East Asia about 203,000. The WHO said that in the Eastern Mediterranean more than 140,000 people have died and in Africa the death toll is slightly above 69,000. In the Western Pacific about 27,500 people have lost their lives.