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HomeA FocusExcess mortality estimates put global COVID deaths at more than 18m

Excess mortality estimates put global COVID deaths at more than 18m

Some 18.2m people have died during the coronavirus pandemic, three times higher than official figures of 5.9m at the end of last year, according to an analysis in The Lancet.

Sweden, which did not lock down, had one of the best excess death rates in Europe, with 91.2 per 100,000, while Bolivia was the world’s highest, at 734 per 100,000.

Low excess mortality rates were estimated across sub-Saharan Africa, with the notable exception of: Eswatini (634.9), Lesotho (562.9), Botswana (399.5), and Namibia (395.6 per 100 000). South Africa’s estimated excess deaths was 302,000 and the estimated excess mortality rate was 293.2 while Zimbabwe’s was 283.6.

Between January 2020 and December 2021, just under 6m COVID-19 fatalities were reported worldwide. But patchy testing, overwhelmed health systems and fragmented death registrations mean this is a vast underestimate.

Instead, the first peer-reviewed estimates of global excess deaths – a measure which tracks how many fatalities were recorded compared to historic trends – suggests there were 18.2m more deaths than expected in the first two years of the pandemic.

The analysis comes two years after the World Health Organization (WHO) first called the COVID-19 outbreak a “pandemic” – though this was six weeks after the UN health agency declared a global health crisis.

The global estimates – compiled by the University of Washington’s Institute for Health Metrics and Evaluation – chime with research (not peer reviewed) from The Economist, the other source tracking COVID-19 excess mortality at a global scale, over a similar time period.

Seven countries accounted for more than half of global excess deaths – India topped the list, with more than 4m fatalities, followed by the United States, Russia, Mexico, Brazil, Indonesia and Pakistan. Among these countries, Russia had the highest excess death rate, at 375 per 100,000 people.

But it is parts of Latin America that have seen by far the world’s worst excess death rate – Bolivia, Peru and Ecuador were all hit incredibly hard by COVID-19, and saw 734, 528 and 333 deaths per 100,000 people, respectively.

The UK ranks roughly in the middle of the global league table of excess death rates, coming 102nd out of 191 countries and territories, placing it at 168 – or 24th worst. However, its excess death rate of 126.8 per 100,000, was very close to the global average of 120 per 100,000, with France on 124.4 and Germany on 120.5.

The indicator also exposes countries which have under-recorded deaths from COVID due to a lack of testing, poor administration or political will.

Study details

Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19- related mortality, 2020–21

COVID-19 Excess mortality collaborators

Published in The Lancet on 10 March 2022

Mortality statistics are fundamental to public health decision-making. Mortality varies by time and location, and its measurement is affected by well-known biases that have been exacerbated during the COVID-19 pandemic. This paper aims to estimate excess mortality from the COVID-19 pandemic in 191 countries and territories, and 252 subnational units for selected countries, from 1 January 2020, to 31 December 2021.

Methods
All-cause mortality reports were collected for 74 countries and territories and 266 subnational locations (including 31 locations in low-income and middle-income countries) that had reported either weekly or monthly deaths from all causes during the pandemic in 2020 and 2021, and for up to 11 year previously. In addition, we obtained excess mortality data for 12 states in India.

Excess mortality over time was calculated as observed mortality, after excluding data from periods affected by late registration and anomalies such as heat waves, minus expected mortality. Six models were used to estimate expected mortality; final estimates of expected mortality were based on an ensemble of these models. Ensemble weights were based on root mean squared errors derived from an out-of-sample predictive validity test. As mortality records are incomplete worldwide, we built a statistical model that predicted the excess mortality rate for locations and periods where all-cause mortality data were not available.

We used least absolute shrinkage and selection operator (LASSO) regression as a variable selection mechanism and selected 15 covariates, including both covariates pertaining to the COVID-19 pandemic, such as seroprevalence, and to background population health metrics, such as the Healthcare Access and Quality Index, with direction of effects on excess mortality concordant with a meta-analysis by the US Centers for Disease Control and Prevention (CDC).

With the selected best model, we ran a prediction process using 100 draws for each covariate and 100 draws of estimated coefficients and residuals, estimated from the regressions run at the draw level using draw-level input data on both excess mortality and covariates. Mean values and 95% uncertainty intervals were then generated at national, regional, and global levels. Out-of-sample predictive validity testing was done on the basis of our final model specification.

Findings
Although reported COVID-19 deaths between 1 January 2020, and 31 December 2021 totalled 5.94m worldwide, we estimate that 18.2m (95% uncertainty interval 17.1–19.6) people died worldwide because of the COVID-19 pandemic (as measured by excess mortality) over that period. The global all-age rate of excess mortality due to the COVID-19 pandemic was 120.3 deaths (113.1–129.·3) per 100, 000 of the population, and excess mortality rate exceeded 300 deaths per 100,000 of the population in 21 countries.

The number of excess deaths due to COVID-19 was largest in the regions of south Asia, North Africa and the Middle East, and Eastern Europe. At the country level, the highest numbers of cumulative excess deaths due to COVID-19 were estimated in India (4.07m [3.71– 4.36]), the USA (1.13m [1. 08–1.18]), Russia (1.07m [1.06–1.08]), Mexico (798,000 [741,000–867,000]), Brazil (792,000 [730,000–847,000]), Indonesia (736,000 [594,000–955,000]), and Pakistan (664,000 [498,000–847, 000]). Among these countries, the excess mortality rate was highest in Russia (374,6 deaths [369·7–378.4] per 100,000) and Mexico (325.1 [301.6–353.3] per 100,000), and was similar in Brazil (186.9 [172.2–199.8] per 100,000) and the USA (179.3 [170.7–187.5] per 100,000).

Interpretation
The full impact of the pandemic has been much greater than what is indicated by reported deaths due to COVID-19 alone. Strengthening death registration systems around the world, long understood to be crucial to global public health strategy, is necessary for improved monitoring of this pandemic and future pandemics. In addition, further research is warranted to help distinguish the proportion of excess mortality that was directly caused by SARS-CoV-2 infection and the changes in causes of death as an indirect consequence of the pandemic.

 

The Lancet article – Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19- related mortality, 2020–21 (Open access)

 

See more from MedicalBrief archives:

 

COVID-19 might have killed four million people in India – Harvard study

 

Pandemic kills more in US than two World Wars and Vietnam

 

Pandemic triggers biggest fall in life expectancy in decades — 29-country study

 

SA and world COVID deaths 3x higher than official figures — The Economist

 

The cost of lockdown: Britain records 70,000 non-COVID ’extra deaths’

 

Death scenarios justifying second UK lockdown 'four times too high'

 

Higher COVID-19 mortality in young Africans than European and US counterparts

 

Analysis suggests that UK's pandemic death toll is twice the official COVID-19 number

 

 

 

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