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

The global death toll from COVID-19 is now 10m, threefold higher than the official estimates, according to a statistical modelling by The Economist. In South Africa, the official COVID death rate of 55,000 people — at 92.7 per 100,000 already the highest in Sub-Saharan Africa — is closer to 159,000.

The Economist estimate is close to figures released last week by the SA Medical Research Council, of so-called "excess deaths", that contradict the official National Department of Health figures.

Official figures say there have been 55,000 COVID-19 deaths in South Africa since 27 March 2020. That puts the country’s death rate at 92.7 per 100,000 people, highest in Sub-Saharan Africa. It is a significant underestimate, reports The Economist, which also puts the global death toll at some 10.2 million rather than the official 3.3 million.

A modelling exercise by The Economist calculates (see below) that there have been seven to 13 million excess deaths worldwide during the pandemic, with the 10.2 estimate in the centre. While the rich world suffered relatively badly, most of the dying has been elsewhere.

“Low as they are in absolute terms, death rates among poor young populations are much higher than they would be for populations in the rich world with similar age profiles,” says the article. “And for the elderly in poor countries the outlook is clearly grim. South Africa has seen 120,000 excess deaths among those over 60.”

The story mentions statistician Ariel Karlinsky at the Israeli think-tank the Kohelet Economic Forum, leader of the respected World Mortality Dataset. He points out that estimates are no substitute for data. According to the Israeli work, writes The Economist: “Only by better tracking of mortality in poor countries can estimates of the death rate be improved.

“Resources should be put into such measures not just to honour the dead and the truth, but also because, without such basic numbers, estimates of other impacts – economic, educational, cultural or in the health of survivors – are hard to understand, or to compare.”

A recent study by the World Mortality Dataset, tracking excess mortality across countries during the COVID-19 pandemic, has been published on MedRxiv, a preprint server for the health sciences. The article is open access, and its results section is run below.

The Economist article that follows that can be accessed through email registration. While normally behind a firm paywall, the respected publication has made its COVID content more accessible in the public interest. Find the link below.

 

The Economist – Modelling COVID-19’s death toll

Over the year to 8 May 2021, South Africa recorded 158,499 excess deaths – that is, deaths above the number that would be expected on past trends, given demographic changes. Public-health officials feel confident that 85% to 95% of those deaths were caused by SARS-Cov-2, the COVID-19 virus, almost three times the official number.

The discrepancy is the result of the fact that, for a death to be registered as caused by COVID-19, the deceased needs to have had a COVID test and been recorded as having died from the disease. Although South Africa does a lot of testing compared with neighbouring countries, its overall rate is still low. And the cause of death is unevenly recorded for those who die at home.

It seems safe to infer that other African data on the disease also undercounts, says

South Africa not unusual

South Africa is not particularly unusual in its levels of testing or in missing deaths outside the medical system. Excess mortality has outstripped deaths officially reported as due to COVID-19, at least at some points in the course of the epidemic, in most if not all of the world.

According to the most recent data, America’s excess deaths were 7.1% higher than its official COVID-19 deaths between early March 2020 and mid-April 2021.

Studies of such mismatches have proved illuminating in some countries. For example, Britain saw excess deaths higher than official COVID-19 deaths during its first wave, but lower than the official COVID death rates in the second – an effect taken to show that measures to stop the spread of COVID had saved lives which in another year would have been lost to other diseases, such as seasonal flu, perhaps. Something similar was seen in France.

But the excess-mortality method has failed to provide useful or robust global figures for the simple reason that most countries, and in particular most poor countries, do not provide excess mortality statistics in a timely fashion.

Global estimates have used the official numbers, despite knowing that the figure – currently 3.3 million – surely falls well short of the true total.

The Economist modelling

To try to put numbers on how much of an underestimate it is – and thus on how great the true burden has been – The Economist attempted to model the level of excess mortality over the course of the pandemic in countries that do not report it.

This work gives a 95% probability that the death toll to date is between 7.1 million and 12.7 million, with a central estimate of 10.2 million. The official numbers represent, at best, a bit less than half the true toll, and at worst only about a quarter of it.

As well as providing a new estimate of the overall size of the pandemic, the modelling sheds light on the distribution of its effects and on its overall course.

Unsurprisingly, most of the deaths caused by COVID-19 but not attributed to it are found in low- and middle-income countries. Our figures give a death rate for the mostly rich countries which belong to the OECD of 1.17 times the official number. The estimated death rate for Sub-Saharan Africa is 14 times the official number, The Economist continues.

And the first-and-second-wave structure seen in Europe and the United States is much less visible in the model’s figures for the world as a whole. Overall, the pandemic is increasingly concentrated in developing economies and continuing to grow.

To create these global estimates of total excess deaths during the pandemic, we drew on a wide range of data. Official counts of COVID-19 deaths, however imperfect they may be, are available for most countries.

Other factors included in The Economist modelling were data on the number of COVID cases and the share of COVID tests that are positive; seroprevalence surveys; steps by governments to curb the spread of the disease; how much people moved around; demography – more younger people typically means lower death rates – systems of government and degree of media freedom.

All told, The Economist collected data on 121 indicators for more than 200 countries and territories. It trained a machine-learning model which used a process called gradient boosting to find relationships between these indicators and data on excess deaths in places where they were available. Or those relationships were used to provide estimates of excess deaths in times and places for which there were no data available. The Economist estimates that by 10 May there was a 95% probability that the pandemic had brought about:

  • 4 million to 7.1 million excess deaths in Asia (official COVID-19 deaths: 0.6 million).
  • 5 million to 1.8 million deaths in Latin America and the Caribbean (v 0.6m).
  • Up to 2.1 million deaths in Africa (v 0.1m).
  • 5 million to 1.6 million deaths in Europe (v 1.0m).
  • 6 million to 0.7 million deaths in America and Canada (v 0.6m).

Despite hitting the poorer parts of the world harder than indicated by data, on a per-person basis COVID-19 really has been worse in richer countries. For Asia and Africa, the average estimated deaths per million people are about half those of Europe including Russia.

 

The World Mortality Dataset: Tracking excess mortality across countries during the COVID-19 pandemic

Ariel Karlinsky and Dmitry Kobak

Affiliations: Hebrew University in Israel and the Institute for Ophthalmic Research at the University of Tübingenin Germany.

Published by MedRxiv on 11 April 2021.

 

Results

Excess mortality

We collected the all-cause mortality data from 89 countries and territories into the openly-available World Mortality Dataset. This includes 47 countries with weekly data, 40 countries with monthly data, and 2 countries with quarterly data. For each country we computed the total excess mortality from the beginning of the COVID-19 pandemic.

The excess mortality was positive and significantly different from zero in 66 countries; negative and significantly different from zero in 4 countries; not significantly different from zero (t < 2) in 17 countries. For 2 remaining countries, there was not enough historic data available in order to assess the significance, but in one of these cases the increase in mortality was very large and clearly associated with COVID-19.

In terms of absolute numbers, the largest excess mortality was observed in the United States (580,000 by 21 February 2021; all reported numbers here and below have been rounded to two significant digits), Russia (440,000 by 28 February 2021), Mexico (400,000 by 14 February 2021), and Brazil (390,000 by 31 March 2021. Note that these estimates correspond to different time points as the reporting lags differ between countries.

Some countries showed negative excess mortality, likely due to lockdown measures and social distancing decreasing the prevalence of influenza. For example, Australia had -4,500 excess deaths and New Zealand had -1,900 deaths. In both cases, the decrease in mortality happened during the southern hemisphere winter season.

As the raw number of excess deaths can be strongly affected by the country’s population size, we normalised the excess mortality estimates by the population size. The highest excess mortality per 100,000 inhabitants was observed in Peru (450), followed by some Latin American and East European countries: Mexico (320), Bulgaria (310), Russia (300), Lithuania (290), Ecuador (280) etc.

Note that many countries with severe outbreaks that received wide international media attention, such as Italy, Spain and the United Kingdom, had lower values.

The infection-fatality rate (IFR) of COVID-19 is strongly age-dependent. As the countries differ in their age structure, the expected overall IFR differs between countries. To account for the age structure, we also normalised the excess mortality estimates by the annual baseline mortality, that is, the expected number of deaths per year without a pandemic event.

This relative increase, also known as a P-score, was by far the highest in Latin America: Peru (114%), Ecuador (63%), Bolivia (55%) and Mexico (52%).

These Latin American countries have much younger populations compared to the European and North American countries, which is why the excess mortality per 100,000 inhabitants there was similar to some European countries, but the relative increase in mortality was much higher, suggesting much higher COVID-19 prevalence.

Undercount of COVID deaths

For each country we computed the ratio of the excess mortality to the officially reported COVID-19 death count by the same date. This ratio differed very strongly between countries. Some countries had ratio below 1, or example 0.6 in France and 0.7 in Belgium.

This is likely because these countries include suspected, and not only confirmed, COVID-19 deaths into their official counts, as well as deaths from other causes in confirmed COVID-19 cases. Another reason for ratios below 1 is that non-COVID mortality may have decreased for example due to influenza suppression, leading to the excess mortality underestimating the true number of COVID deaths.

Nevertheless, most countries showed ratio above 1, suggesting an undercount of COVID-19 deaths. Importantly, in many different countries the correlation between weekly reported COVID-19 deaths and weekly excess deaths was very high.

This included countries with undercount ratios below 1 (e.g. France, r = 0.79; Belgium, r = 0.89), as well as countries with undercount ratio above 1 (e.g. Spain, undercount ratio 1.2, r = 0.86; United States, undercount ratio 1.2, r = 0.74; Mexico, undercount ratio 2.3, r = 0.80; Peru, undercount ratio 2.7, r = 0.89).

The correlations were often higher during the first wave alone (measured until the end of June 2020): e.g. r = 0.96 in Belgium, r = 0.87 in France, r = 0.97 in Spain. High correlations suggest that excess mortality can be fully explained by COVID-19 mortality, even when it is consistently underreported in some countries.

Interestingly, in most countries the undercount ratio was not constant across time, e.g. in the United Kingdom it was above 1 during the first wave but below 1 during the second wave, coincidentally leading to the overall undercount of 1.0 at the time of writing.

Similarly, in Spain the undercount ratio was very high during the first wave, but around 1 during the second wave, leading to the overall undercount of 1.2 at the time of writing. This decrease of the undercount ratio may be partially due to improved COVID death reporting, and partially due to the excess mortality underestimating the true COVID mortality in winter seasons due to influenza suppression.

The undercount ratio typically stayed within 1–3 range, but some countries showed much larger values. We found the highest undercount ratios in Tajikistan (100), Nicaragua (50), Uzbekistan (30), Belarus (14) and Egypt (13). Such large undercount ratios strongly suggest purposeful misdiagnosing or underreporting of COVID-19 deaths, as argued for the case of Russia (undercount ratio 5.2).

Summing up the excess mortality estimates across all countries in our dataset gives 3.3 million excess deaths. In contrast, summing up the official COVID-19 death counts gives only 2.1 million deaths, corresponding to the global undercount ratio of 1.56.

It is likely that among the countries for which we could not obtain the data the undercount is much higher, so we believe that 1.56 is a conservative lower bound on the global undercount ratio of COVID-19 deaths. At the time of writing, the world’s official COVID-19 death count is 2.9 million. Our results suggest that the true toll may be above 4.5 million.

 

The Economist story – Modelling COVID-19’s death toll (Restricted access)

MedRxiv article – The World Mortality Dataset: Tracking excess mortality across countries during the COVID-19 pandemic (Open access)

 

SEE ALSO FROM THE MEDICALBRIEF ARCHIVES

 

More than 20% of COVID deaths at some UK hospitals follow on ward infections

SAMRC: Eastern Cape COVID death rate may be world’s worst

Increased risk of death and serious illness among COVID-19 survivors

Sunlight associated with lower COVID-19 deaths — Edinburgh University

 

 

 

 

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