Excess mortality exceeds reported deaths from COVID-19

Nearly 1 million excess deaths have been recorded in 2020 in 29 high-income countries, with age-standardized excess death rates being higher in men than in women, a study has shown. Sex inequality in mortality has further widened in most countries in 2020.

“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 said. “Many countries had lower deaths than expected in children [aged] <15 years.”

This time series study included the following high-income countries: Austria, Belgium, Czech Republic, Denmark, England and Wales, Estonia, Finland, France, Germany, Greece, Hungary, Israel, Italy, Latvia, Lithuania, the Netherlands, New Zealand, Northern Ireland, Norway, Poland, Portugal, Scotland, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, and the US.

The researchers obtained and disaggregated by age and sex mortality data from the Short-term Mortality Fluctuations data series of the Human Mortality Database for 2016–2020. They estimated weekly excess deaths (observed vs expected deaths predicted by model) in 2020 by sex and age (0–14, 15–64, 65–74, 75–84, and ≥85 years) using an over-dispersed Poisson regression model that accounted for temporal trends and seasonal variability in mortality.

Approximately 979,000 (95 percent confidence interval [CI], 954,000–1,001,000) excess deaths occurred in 2020 in the 29 countries analysed. All countries had excess deaths, except for New Zealand, Norway, and Denmark. [BMJ 2021;373:n1137]

The top 5 countries with the highest absolute number of excess deaths were as follows: US (458,000, 95 percent CI, 454,000–461,000), Italy (89,100, 95 percent CI, 87,500–90,700), England and Wales (85,400, 95 percent CI, 83,900–86,800), Spain (84,100, 95 percent CI, 82,800–85,300), and Poland (60,100, 95 percent CI, 58,800 to 61,300). Notably, New Zealand recorded a lower overall mortality than expected (–2,500, 95 percent CI, –2,900 to –2,100).

“In many countries, the estimated number of excess deaths substantially exceeded the number of reported deaths from COVID-19,” the researchers said.

In men, the highest excess death rates (per 100,000) were in Lithuania (285, 95 percent CI, 259–311), Poland (191, 95 percent CI, 184–197), Spain (179, 95 percent CI, 174–184), Hungary (174, 95 percent CI, 161–188), and Italy (168, 95 percent CI, 163–173), and the highest rates in women were in Lithuania (210, 95 percent CI, 185–234), Spain (180, 95 percent CI, 175–185), Hungary (169, 95 percent CI, 156–182), Slovenia (95 percent CI, 132–184), and Belgium (151, 95 percent CI, 141–162).

“Little evidence was found of subsequent compensatory reductions following excess mortality,” the researchers said.

The case of New Zealand as being the only country with a lower than expected mortality across all the age groups, in both men and women, with no sex difference in excess death rates, could potentially be attributed to the country’s elimination strategy early in the pandemic. [N Engl J Med 2020;383:e56; Med J Aust 2020;213:198-200.e1]

“Our study adds important insights on the direct and indirect effects of the COVID-19 pandemic on total mortality,” the researchers said. “It underscores the importance of availability of age and sex disaggregated data for more nuanced analysis and estimation of the direct and indirect effect of the pandemic.”

Excess death is calculated as the difference between the number of deaths from all causes that occurred during the pandemic and the expected number of deaths based on a historical baseline from recent years. [https://www.cdc.gov/nchs/nvss/vsrr/covid19/excess_deaths.htm; Nat Med 2020;26:1919-28]