US Coronavirus Death Toll Is 'A Substantial Undercount' Of Actual Numbers, Yale Study Reveals

Health experts have always warned the daily death toll from COVID-19 in the United States undercounts the true number by a large amount, because this metric is a lagging indicator and the cause of death is not always very clear. As a consequence, the 131,000 COVID-19 related deaths in the U.S. reported Wednesday could be substantially lower than the true death toll, probably by as much as 30%.

In a study published in the peer-reviewed medical journal JAMA Internal Medicine, researchers from Yale University compared the number of excess deaths in the U.S. from any cause with the reported weekly COVID-19 deaths for the period March 1 to May 30. They then compared these numbers with the number of deaths from the same period in previous years.

What they found was that the excess number of deaths over normal levels was also higher than the deaths attributed to COVID-19. This finding led the Yale team to conclude many of those fatalities were likely caused by COVID-19 but not confirmed as so.

They said reporting discrepancies by individual states and a substantial increase in deaths suggest the number of COVID-19 fatalities is undercounted but not intentionally.

“Our analyses suggest that the official tally of deaths due to COVID-19 represent a substantial undercount of the true burden,” Dan Weinberger, an epidemiologist at Yale School of Public Health and a lead author of the study, told CNBC.

Weinberger said other factors contributed to the increase in deaths, like avoiding surgeries, but these don't equate to the astronomical surge in deaths.

The Yale data shows the 781,000 total deaths in the U.S. from March 1 to May 30 were nearly 19% higher than what would normally be expected. Also, the number of excess deaths from any cause was 28% higher than the official tally of COVID-19 deaths during those three months.

Of the 122,300 excess deaths, 95,235 were blamed on COVID-19. The Yale researchers said most of the rest of the excess deaths were likely related to, or directly caused, by COVID-19.

Researchers said the increase in excess deaths in many states lagged behind an increase in outpatient visits from people reporting an “influenza-like illness.”

They pointed out the gap between reported COVID-19 deaths and the excess deaths varied by state. For example, California reported 4,046 COVID-19 deaths and 6,800 excess deaths, leaving 41% of the excess deaths unattributed to COVID-19.

Texas and Arizona had wider gaps. The difference between reported COVID-19 deaths in Texas was 55%. It stood at 53% in Arizona. California, Texas and Arizona are among the four states (the other being Florida) that together account for more than half of all new COVID-19 cases reported in the U.S. since last week.

"Excess deaths provide an estimate of the full COVID-19 burden and indicate that official tallies likely undercount deaths due to the virus. The mortality burden and the completeness of the tallies vary markedly between states," the study concluded.