IHME estimates COVID deaths more than double official reports

It is widely known that COVID-19 deaths worldwide are likely vastly underreported due to reasons such as health system limitations, but now a highly regarded research institute at the University of Washington School of Medicine has sought to quantify how great the difference really is.

New analysis released by the Institute for Health Metrics and Evaluation (IHME) has found COVID-19 deaths are significantly underreported in almost every country, estimating the pandemic has caused 6.9 million deaths.

This compares to 3.27 million reported deaths from the virus since the outbreak began.

The IHME reached its conclusion based on its long-standing methodology for measuring the burden of diseases on a global scale, which it has been running to calculate the total human cost of diseases since 1990.

The process starts with a benchmark of what death rates would have looked like if there were no pandemic, comparing the actual number of all-cause deaths with anticipated deaths from all causes based on pre-pandemic trends.

This subtraction gives an "excess mortality" figure, which is then adjusted to remove deaths that are indirectly attributable to the pandemic such as people with non-COVID conditions avoiding health care facilities.

The resulting number is then followed by an adjustment for an estimated number of deaths averted by the pandemic itself, for example traffic death declines due to lower mobility.

The institute's researchers believe this method yields a better reflection of how many deaths are directly due to the SARS-CoV-2 virus which causes COVID-19.

"As terrible as the COVID-19 pandemic appears, this analysis shows that the actual toll is significantly worse," said IHME's director Dr Chris Murray.

"Understanding the true number of COVID-19 deaths not only helps us appreciate the magnitude of this global crisis, but also provides valuable information to policymakers developing response and recovery plans."

The updated analysis shows the US has had more COVID-19 deaths to-date than any other country, with a total of more than 950,000.

Among the world's worst-hit nations, the IHME estimates real death numbers are close to triple the reported levels for India, Mexico and South Africa, and more than five times greater for Russia. 

Many deaths from COVID-19 go unreported because countries only report deaths that occur in hospitals or in patients with a confirmed infection. In many places, weak health reporting systems and low access to health care magnify this challenge.

IHME's analysis found that the largest number of unreported deaths occurred in countries that have had the largest epidemics to-date. However, some countries with relatively smaller epidemics saw a large increase in the death rate when accounting for unreported deaths. This analysis shows that they may be at greater risk for a wider epidemic than previously thought.

"Many countries have devoted exceptional effort to measuring the pandemic's toll, but our analysis shows how difficult it is to accurately track a new and rapidly spreading infectious disease," Murray said.

"We hope that today's report will encourage governments to identify and address gaps in their COVID-19 mortality reporting, so that they can more accurately direct pandemic resources."

The institute is forecasting more than 5 million reported deaths from COVID-19 by 1 August, although through its burden of disease analysis trend line the death toll could reach more than 9 million by then.

Updated at 4:46pm AEST on 7 May 2021.