The US has the worst confirmed COVID-19 death toll in the world, but it's likely for every two counted there's another that hasn't been attributed to the pandemic, a new study has found.
Keeping track of the number of confirmed deaths in a pandemic is difficult - an estimate of the true death toll for 2009's swine flu pandemic, for example, wasn't determined until a couple of years after it subsided. The official confirmed death toll was 18,449, but researchers found it was more likely to be up to 575,000.
They worked this out by looking at excess mortality numbers - how many more people died than would have under usual circumstances.
Researchers have now done that for the US between March and August this year, and found 20 percent more deaths than there should have been. Problem is, only two-thirds of them had COVID-19 listed as the cause of death, suggesting the true toll could have been underestimated by 50 percent.
"Contrary to skeptics who claim that COVID-19 deaths are fake or that the numbers are much smaller than we hear on the news, our research and many other studies on the same subject show quite the opposite," said lead author Steven Woolf of Virginia Commonwealth University's Center on Society and Health.
More than 220,000 deaths in the US this year have been confirmed in people infected with the virus.
The researchers say of the likely 110,000 other deaths, perhaps not all would have been infected - but still victims of the pandemic, in a way.
"Some people who never had the virus may have died because of disruptions caused by the pandemic," said Dr Woolf. "These include people with acute emergencies, chronic diseases like diabetes that were not properly cared for, or emotional crises that led to overdoses or suicides... And death is only one measure of health. Many people who survive this pandemic will live with lifelong chronic disease complications.
"Imagine someone who developed the warning signs of a stroke but was scared to call 911 for fear of getting the virus. That person may end up with a stroke that leaves them with permanent neurological deficits for the rest of their life."
The study found an increase in deaths from dementia and heart disease that followed the same pattern as deaths from the coronavirus. All-cause mortality increased as the virus' second wave began in the US, which the data showed followed early reopenings - lives saved in reduced car accidents, for example, were vastly outnumbered.
"These deaths reflect a true measure of the human cost of the Great Pandemic of 2020," an editorial published alongside the study in the journal JAMA said.
"These deaths far exceed the number of US deaths from some armed conflicts, such as the Korean War and the Vietnam War, and deaths from the 2009 H1N1 (swine flu) pandemic, and approach the number of deaths from World War II...
"It is critical to consider that for every death, an estimated nine family members are affected, such as with prolonged grief or symptoms of posttraumatic stress disorder. In other words, approximately 3.5 million people could develop major mental health needs.
"This does not account for the thousands of health care workers in hospitals and nursing homes who have been witness to the unimaginable morbidity and mortality associated with COVID-19."
Contributing to the United States' high death toll has been an unusually high mortality rate - more people as a percentage of the population dying of COVID-19 than in other countries with huge outbreaks.
A separate study, also published in JAMA, wanted to find out if that was because the US had an "early surge of cases prior to improvements in prevention and patient management" or simply had a "poor long-term response".
The University of Pennsylvania researchers found even after the early peak, the US' mortality rate from COVID-19 has remained higher than other OECD countries with outbreaks, such as Italy.
More than 180,000 Americans might be alive today if the US had a similar mortality rate to Australia, they said.
"This may have been a result of several factors, including weak public health infrastructure and a decentralised, inconsistent US response to the pandemic."