Almost one million extra deaths related to Covid-19 were recorded in 29 high-income countries last year, a new study has found.

The countries examined included Northern Ireland, England, France, Germany, the Netherlands, Norway, New Zealand and the US.

According to the findings, all 29 countries, except for Norway, Denmark and New Zealand, recorded more deaths than expected in 2020. A total of 979,000 excess deaths were found to have occurred.

The five countries that were found to have the highest absolute number of excess deaths were the US (458,000), the UK (specifically England and Wales - 94,400), Italy (89,100), Spain (84,100) and Poland (60,100).

New Zealand recorded fewer overall deaths than expected (-2,500).

The total number of excess deaths was found to have occurred largely among people over the age of 75, followed by those aged 65-64.

The researchers from Oxford University in the UK found that in most countries, the number of estimated excess deaths exceeded the number of reported deaths from Covid-19. For example, in the UK, estimated excess deaths were at least 30% higher than the number of Covid-related deaths.

However, some countries, such as France, reported a higher number of Covid-related deaths than estimated excess deaths. The reason for this was unclear, but the researchers suggested that it may be related to differences in how different countries define and record Covid deaths.

Meanwhile, the study also found that excess death rates were higher among men in almost all countries.

“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 said.

They added that work will be needed in the future to understand the impact of national vaccination programmes on mortality in 2021.

Details of their findings are published in The BMJ. In a linked editorial, researchers from Imperial College London said that the study confirms “the huge toll of the Covid-19 pandemic on mortality in high-income countries”.

However, they warned that the full impact of the pandemic “may not be apparent for many years, particularly in lower income countries where factors such as poverty, lack of vaccines, weak health systems, and high population density place people at increased risk from Covid-19 and related harm”.