Nearly 1 million more people than normal died in 29 high-income countries during the COVID-19 pandemic in 2020, according to a time series study yesterday in BMJ.
University of Oxford researchers led the study, which involved calculating weekly excess deaths for each included country in 2020, adjusting for age, sex, and seasonal and annual mortality trends in the previous 5 years.
They estimated that 979,000 more people than expected died of all causes during the pandemic, with rates generally increasing with advancing age. All countries, except for Demark, New Zealand, and Norway, had more deaths than expected, especially in men. But the excess death rate in the United States was higher among women than men in the 85 and older age-group.
"Excess deaths substantially exceeded reported deaths from COVID-19 in many countries, indicating that determining the full impact of the pandemic on mortality requires assessment of excess deaths," the researchers wrote.
Risk factors for death
Fewer deaths than expected (2,500 fewer) were recorded in New Zealand. Five countries—Italy (89,100 extra), Poland (60,100), Spain (84,100), the United Kingdom (94,400), and the United States (458,000)—had the most excess deaths.
Countries with the highest excess death rates per 100,000 among men included Belgium, Hungary, Italy, Lithuania, Poland, and Spain, while those with the highest rate among women were Belgium, Hungary, Lithuania, Slovenia, and Spain.
Coinciding with known COVID-19 peaks, many countries in the northern hemisphere experienced surges of excess deaths in March to May and October to December 2020. In spring, excess deaths spiked in Belgium, Italy, the Netherlands, Northern Ireland, Spain, and the United Kingdom, rising more than 50% during some weeks. In fall and winter, excess deaths rose markedly in Austria, Belgium, the Czech Republic, Hungary, Italy, Lithuania, Poland, Slovakia, Slovenia, and Switzerland.
The estimated number of extra deaths in most countries was higher than the number of reported COVID-19 deaths—more than 30% higher in both the United Kingdom and the United States. But countries such as France and Israel reported twice as many coronavirus deaths than estimated excess deaths, while Lithuania and South Korea attributed only 20% of excess deaths to COVID-19. The authors said these differences may be related to differences in COVID-19 testing and case reporting.
Most excess deaths were among people 75 years or older, followed by those 65 to 74. Deaths among children younger than 15 were close to the expected number and were lower in some countries.
The authors said that their study underscores the need for detailed analyses that consider the roles of possible sources of social inequity, such as race and socioeconomic status, as well as the effects of national vaccination rollouts on 2021 deaths.
"Reliable and timely monitoring of excess deaths would help to inform public health policy in investigating the sources of excess mortality in populations and would help to detect important social inequalities in the impact of the pandemic to inform more targeted interventions," the researchers concluded.
Excess mortality only part of puzzle
In a linked editorial, Jonathan Clarke, MBBChir, PhD, MPH; Azeem Majeed, MD; and Thomas Beaney, MBBS, all of Imperial College London, said that excess deaths alone offer an incomplete picture of the effects of the COVID-19 pandemic on nations' health, "particularly among younger people in whom death from COVID-19 is rare," they wrote.
"The importance of 'long COVID,' for example, has recently been highlighted, but the true burden of this condition has yet to be quantified, and policies are urgently needed to overcome its long term challenges," they added.
Clarke and colleagues also noted that the effects of pandemic-related healthcare system disruptions are likely to be felt for years to come, especially in areas in which COVID-19 remains endemic and in poor regions with strained healthcare resources, a lack of vaccines, and high population density.
"Finally, although mortality is a useful metric, policy informed by deaths alone overlooks what may become a huge burden of long term morbidity resulting from COVID-19," they concluded. "An urgent need exists to measure this excess morbidity, support people with long term complications of COVID-19, and fund health systems globally to tackle the backlog of work resulting from the pandemic."